Alex, Julie, Jack and Katie Power fly over the moonlit streets of Manhattan using their various superpowers. Jack, the second youngest of the team of super-powered siblings, cannot believe they left their schoolbooks in the sewer after rescuing that helpless kitten. The youngest, Katie, cannot believe they’re actually going back for the books. She pulls the rescued kitten close to her face and asks her older brother Alex what they should do with the kitty. Alex has no idea; it just figures their mother would happen to be allergic to the animal they saved. He suggests they find someone else to take care of the kitten. At least they saved it from the alligators in the sewers, Julie says. Once more, she insists she heard some sort of piper music in the sewer right before the alligators left—and that the alligators were wearing collars. She just wishes her siblings believed her.
After the four siblings land, Jack Power, also known as Mass-Master, tells Julie she is out of her gourd. She must have been so scared that she hallucinated! He was just as scared, Julie insists. They all were; they got separated and couldn’t find each other. She suggests they practice using their powers more so it doesn’t happen again.
Julie then takes the kitten from Katie and asks her little sister to power up by disintegrating some matter. Katie, enthusiastically grabbing hold of a dirty old mattress in the alleyway, begins glowing brightly as she converts its mass into energy. She asks if her light has illuminated the sewers yet. Alex, the gravity-altering member of Power Pack known as Gee, effortlessly lifts the manhole cover over his head. He tells his sister her light lets him see inside the sewer—but he cannot say the same for Jack, who is already down in the depths. Try as he might, Jack just can’t find their books.
Energizer comes closer to the manhole and sheds some light inside. “All right, pig nose. Can you see them now?” she asks her brother. Alex asks his quarreling siblings to cool it; Power Pack is a team, and therefore needs to act like one. He seconds Julie’s recommendation they better hone their abilities. They have managed to defend themselves against threats like alligators and rudimentary villains, but what happens if they encounter an actual supervillain?
Mass-Master suddenly pops his cloudy head out of the manhole and gives his siblings some bad news. Their books are all gone! Incredulous, the Power kids climb down into the sewer to see for themselves, while Gee continues yammering away about their roles as superheroes. He now recommends they better guard their secret identities, starting with using only their codenames whenever they’re in-costume. Lightspeed, meanwhile, confirms what Mass-Master reported: their books are indeed gone. She asks what might have happened to them. Jack guesses the alligators took them.
Up above, the manhole cover suddenly slams shut. The kids look up in horror. It couldn’t have closed by itself, Julie says. Once again, she begins hearing the same music she heard last time. She tells her brothers and sisters to listen. By then, however, it’s pointless, as the source of the music emerges from the shadows. “You’re right, my dear! The manhole cover did have a bit of help!” the Morlock Piper says. “Annalee—and the other Morlocks—will be glad you are bright as well as beautiful!” Ape, a grungy Morlock with simian facial features reaches to grab the kids.
Meanwhile, Nightcrawler and Shadowcat of the X-Men work their way through the cluttered, dimly lit Morlock tunnels. Kurt asks Kitty if she supposes the Morlocks ever considered clearing out this clutter. Kitty assumes they like the passage obstructed; anyone without the mutant powers to bypass them would make so much noise, the Morlocks would hear them coming from miles away. That must be why the Morlocks asked them to use this particular entrance, Kurt supposes. That, and because it’s yucky, Kitty adds. Callisto, after all, has never quite forgiven Storm for wresting control of the Morlocks from her, and resents that she only gets to lead them because Storm ordered it.
Surely Callisto doesn’t completely detest the X-Men, Kurt says. She did have her Morlock healer save Xavier’s life after he was brutally beaten. In a way, Kurt supposes Callisto actually admires Storm! He hopes Callisto likes the gift he brings her. Likewise, Kitty hopes Caliban likes her present as well.
Nightcrawler and Shadowcat reach the end of the tunnel, which opens up into a wide cavern. Kitty takes the ladder to the floor. Kurt, on the other hand, teleports to the center of the room, where Callisto awaits. “Callisto! How lovely to see you again!” he says as he reappears in front of her. After greeting him in return, she asks what brings him to the tunnels. Nightcrawler kisses her on the hand and presents her with some postcards from Storm. He tells Callisto that Storm, currently overseas in Africa, requested Kurt personally deliver these cards to Callisto—along with her personal thanks for saving the professor’s life.
Shadowcat, meanwhile, heads straight over to Caliban and gives him a gift as well. She feels guilty bringing him a present when she knows he actually wants her love. “Do not torture yourself over it, Kittypryde!” Caliban says. “A person can only give what he has—this much Caliban has learned!” Kitty takes comfort in his words. However, she tells him she recently took a trip to Japan and learned a few things—most importantly the value of her friends. Caliban understands. He also understands Storm’s sound reasoning behind her mandate that the Morlocks no longer kidnap surface-dwellers. However, he is glad he once did it, for that is how he met Kitty Pryde.
After their discussion, Caliban opens up his gift: a new Japanese T-shirt. He insists it’s too nice for him! Kitty doesn’t think so, and neither does her companion Lockheed, the so-called dragon of sartorial elegance. Caliban puts the shirt on over his clothes. While his fellow Morlocks crowd around and compliment his new threads—which sport a symbol of the Japanese rising sun superimposed with the word Sushi!—Caliban says thanks to Kitty, his friend.
Meanwhile, miles away, the menacing group of Morlocks closes in on the cornered Power kids. “Can’t go up! Can’t go down! And Morlocks lurking all around!” the adhesive Morlock Tar Baby says. This is why she suggested they practice using their powers more, Lightspeed says. Gee thinks the Morlocks represent the perfect opportunity to do just that. He degravitizes himself, floats up to remove the manhole cover, and tells Lightspeed to get ready to extract Energizer.
Meanwhile, the Ape lunges for Mass-Master and grabs hold of his body. Got him, Ape says! To his surprise, Mass-Master turns into a cloud of vapor and slips out of his grip. In the back corner, Energizer tells Tar Baby and Piper to back off before she fires her power balls at them. She hurls one of these balls at Erg, the eyepatch-wearing Morlock with impossibly upright hair. Much to her surprise, he catches it. Nobody has ever done that before! Energizer exclaims. In response, Erg introduces himself and explains his mutant power; he absorbs energy directly and expels it through his electric eye. He gives the kids a demonstration. A stream of electricity erupts from his left eye socket and zaps Alex Power out of the air.
Katie screams as her brother falls, but Piper, the bearded Morlock responsible for the eerie music, asks her not to worry; her brother will recover, none the worse for wear. He puts out his arms and gently catches the falling lad. Erg puts his arms around Energizer and asks her to consider living among the Morlocks for a while. They can train her to better use her powers, as Erg moderates his own. She can decide that later, however. For now, Erg wants both captured children unconscious.
Lightspeed and Mass-Master, the last two Power Packers standing, try to formulate a plan of attack. Lightspeed orders her little brother to make himself super-dense and stop Tar Baby while she tries to slow herself down. Unfortunately, the wild kitten gnawing on her shoulder makes it difficult to concentrate. Mass-Master does as he is told and throws himself at Tar Baby’s head while condensing himself to his most compact form. He lands in Tar Baby’s natty hair, attempting to knock him out with his Jack Hammer special. To his surprise, he gets stuck in the sticky follicle mass. Tar Baby laughs. “As you see, whatever touches, sticks to me!” Tar Baby says. “Can’t go near, can’t go far, trapped like butterflies in a jar.”
Tar Baby’s use of the word “jar” gives his teammate Ape an idea. While Julie Power charges at him full-throttle, Ape transforms his entire body into an oversized glass jar and opens his lid. Lightspeed barrels right into the trap, at which point Ape shuts the lid. She squeals when she realizes she is inside the dirty Morlock’s body. Ape, turning his head inward, introduces himself to his prisoner and explains his power. He can turn into anything he thinks of—only he can’t think of much! He relies on his friend Tar Baby for suggestions.
At his sister’s suggestion, Mass-Master turns his body cloudy and escapes from the adhesive clutches of Tar Baby’s hair. Ape turns to flee, but takes time to tell the two kids they shouldn’t be in the sewers alone, as it’s not safe. On the other hand, the surface isn’t exactly safe for mutants either, he adds. Mass-Master charges at the escaping Ape. He orders him to release his sister. Ape doesn’t know what to do. “Like Teflon coating, clouds don’t stick,” Tar Baby says. “Better make a funnel quick!” Picking up on the hint, Ape takes a deep breath and converts his mouth into a funnel. He absorbs the approaching Mass-Master and traps him in the glass jar as well.
“Darn! We really blew it this time,” Julie says as the Morlocks carry her and her three captured siblings back to their home. Piper tells her it’s a case of eye for an eye; the surface-dwellers killed Annalee’s kids, so in return, the Morlocks have taken it upon them to refresh their ranks. Ape asks if they can take the shortcut home; he can’t wait for Annalee to see these new kids! Erg supports this idea. After all, the sooner Annalee gets some new kids, the sooner she will feel happy again—and the sooner the Morlocks will be rid of rotten little Leech.
Meanwhile, not too far away, Nightcrawler and Shadowcat say goodbye to Callisto and thank her for accompanying them to the exit. “Thanks for coming, handsome!” she replies. “Professor Xavier’d do well to employ you as messenger more often! If you ever tire of those wimpy X-Men, there’s a place for you among the Morlocks!” Kurt promises to keep it in mind. Again, he says goodbye and begins walking away with Kitty. Right as they leave, however, Ape, Tar Baby, Piper and Erg return with the captured Power children. Kitty doesn’t notice; she is too busy teasing Nightcrawler about the obvious crush Callisto has on him. Lockheed, meanwhile, flies over to the returning Morlocks and hassles them.
Kurt hears the commotion and turns around in time to see Lockheed pestering the jar-shaped Ape. Ape stupidly tries to shoo Lockheed away with his lid, a move that allows the Julie and Jack Power to escape. The kids laugh as they flee; they knew Ape was dumb! They fly down a darkened side-tunnel in order to get away from the sheer number of Morlocks in their vicinity. Finally, Kitty turns around to see what is bothering her pet dragon. Kurt tells her he swears he saw two children fly out of a walking jar. Who were they? he asks Caliban. Caliban explains those are the Drain Dwellers, a group of Morlocks with whom Callisto forces Annalee and Leech to stay. This tunnel leads to their home. However, he tells Kurt he must be mistaken about seeing children; there are no kids left in the Morlock alley ever since Annalee’s children died. Kurt has already heard this story; Professor X told them about it. Although he sympathizes with this loss, he knows what he just saw.
In the Drain Dweller tunnel, the four kidnappers struggle to recapture their escapees. Mass-Master, having learned from past mistakes, formulates a new plan of attack. He tells his older sister to steer clear of both Tar Baby and Erg for now. He then charges at Erg in his vapor form, solidifies and condenses his body, and collides with the top of Erg’s head with all the speed of a well-thrown brick. Erg drops Alex. Meanwhile, Lightspeed goes after Piper, and knocks her sister out of his hands. The four reunited siblings grab hold of each other and fly through the tunnels toward the surface.
They don’t make it very far before each of their powers cut out inexplicably. The airborne Lightspeed crashes to the ground, dropping Gee and Energizer in the process. Mass-Master’s cloud form dissipates and he falls as well. From behind, the Drain Dwellers approach the escaped children, thanking someone named Leech for the intervention. On the other side, a group of Morlocks approaches. Piper presents the kids to Annalee. She thanks him for bringing her such beautiful children.
Annalee, a tender-looking old woman in traditional—if mismatched—farmwife clothes, leans down and greets her new children. She helps Katie off the ground, somehow addressing her by her first name. Katie is stunned. How does Annalee know her name? Annalee explains she knows all about the children from reading their schoolbooks! So much for their secret identities, Alex pouts. Annalee tells him not to worry. The Morlock Beautiful Dreamer will give them much better secret identities; so much better, in fact, that Power Pack won’t even remember who they are! Julie asks what she means; Jack asks why Julie even cares. He turns to Annalee and tells her she better let them go before their parents get worried and call the police.
Beautiful Dreamer, a timid young girl dressed in a pink prom dress and a veiled top-hat, suddenly realizes these captured children come from the surface world. Callisto has forbidden them to kidnap surface-dwellers, she says! Piper corrects her thinking. They didn’t raid the surface; they found these kids in the storm drains. Besides, they owe Annalee a debt, as her kids were running errands for the Drain Dwellers when they disappeared. Soon, he says, Masque will come rearrange Power Pack’s faces, while Beautiful Dreamer will alter their memories. They won’t remember they’ve had any home but the alley, or any parent but Annalee!
Meanwhile, several levels above, Nightcrawler and Shadowcat finally part ways with Caliban and wave goodbye. Kitty thinks he really loved her gift. Caliban would love any gift Kitty gave him, Kurt reminds her. Kitty sighs. She’s barely fifteen, yet she already has all these problems with love! It makes her feel so old. Anyway, she asks Kurt if they can start home already. No, he tells her. He sensed something fishy happening back in the tunnels that he wants to investigate.
A few minutes later—and several levels below in a Morlock lounge—the Morlocks stand around a barrel fire, talking as usual, while Leech snuggles affectionately with Power Pack’s rescued kitten. Power Pack, meanwhile, struggles to come free of their bindings. Alex suggests they get free before the Masque guy arrives. Energizer tries to incinerate their bindings, but finds her powers still do not work. It’s because of Leech, Jack says. His presence dampens their powers; as long as he is around, they can’t do anything! Alex suggests they get rid of him. Taking his cue, Jack, the best knot-master in his Cub Scout troop, begins working free from his bindings. If he can just get one kid untied, they can get free, Alex tells him.
Not far away, Nightcrawler, Shadowcat and Lockheed approach the heavy, metal door blocking the chamber of the Drain Dwellers. Kitty tries to phase through it, but finds she can’t. It doesn’t surprise her; the same thing happened to her last time she visited the Morlocks. She knows Leech is responsible, but asks an interesting question: what kind of powers must Annalee have that the Morlocks need Leech to constantly block them?
On the other side of the door, Masque finally arrives, intent on repaying his debt to Annalee. The hideous, disfigured Morlock slinks over to the Power siblings and asks if they want to have a face like his. No, Julie shouts! Somehow free of her bindings, she springs sideways, knocks Leech out of the way, and grabs his kitten. Come get the kitten, she says as she runs down a dark alleyway. “No. Lonely,” Leech cries. He chases her into the tunnel. “Come back.”
With Leech gone, Power Pack suddenly regains access to their powers. Likewise, Kitty Pryde now tumbles through the door and into the Morlock lair. Kurt, on the other hand, notices something else: he feels waves of total misery washing over him. Kitty feels it too; thankfully, Professor X trained them in how to resist psychic attacks.
The Power siblings begin fighting back. Energizer hurls a ball of energy at Masque while Mass-Master scouts out the rest of their enemies. Alex, however, suddenly begins feeling inexplicably miserable. Sure enough, the empathic projector Annalee is crying over her new children’s misbehavior, and her sadness permeates the room. Erg suggests they get Leech back in the room as fast as possible; Annalee’s projecting such misery that the Morlocks, Callisto included, will feel it on the other side of the alley!
Piper tells his friends to fight their sadness and capture the kids. Ape asks how. “Gobble up the little tots, just like Pac Man’s little dots!” Tar Baby suggests. Adopting this idea, Ape transforms into an oversized version of Pac Man with arms and legs: circular, two-dimensional, with his mouth agape. He tries to engulf Gee, but the clever kid degravitizes himself and floats to the ceiling. Piper, meanwhile, chases after Energizer. If the kids escape, the Drain Dwellers will be stuck with Annalee—and Leech—forever, he shouts! Gee propels himself at Piper and hits him in the back. With him out of the way, he asks Energizer to incinerate his bindings. At this time, Mass-Master rejoins his two siblings. Alex, Jack and Katie vow to find their sister Julie and get out of the tunnels as soon as possible.
Erg, zapping the ground at their feet with a surge of electricity, doesn’t intend to let Power Pack go so easily. Fortunately for them, at this time, Nightcrawler and Kitty move through the wall and arrive in the Drain Dwellers’s lair, right in the middle of the fracas. Kitty finally believes what her teammate claims he saw. There are children in here—all of whom even have superpowers—and they’re younger than she is, Shadowcat says.
Power Pack mistakes the new arrivals for additional Morlocks. “And this one smells worse than the others!” Mass-Master says. He plugs his nose to dampen Nightcrawler’s sulfuric stench. Shadowcat tells the kids not to worry; she and Nightcrawler are X-Men, and that smell is just what happens when Nightcrawler teleports. Nightcrawler ignores them and confronts Masque. Why are the Morlocks now kidnapping surface children? Instead of answering, the Drain Dwellers attack in full-force. They can’t risk the X-Men escaping and letting Callisto know of their actions by way of Storm. Erg strikes at them with his electricity, but Kitty and Nightcrawler elude his attack.
Meanwhile, Lightspeed continues to lure Leech away from the rest of them down a long, winding tunnel. “Mine. Please. Give,” Leech tells her, referring his kitten friend. “Alone. Like poor Annalee.” Julie grumbles and asks what’s so poor about Annalee.
Back in the Morlock lounge, Nightcrawler tumbles and teleports around the room, evading the various Morlock attacks while interrogating them for answers as he goes. Ape fesses up. He explains what happened to Annalee’s kids, and how when she feels bad, everyone feels bad! Nightcrawler immediately understands. Annalee must be a projecting empath, hence the need to have Leech with her at all times. Meanwhile, Shadowcat, Mass-Master and Gee try to neutralize Tar Baby’s threat. Kitty lures him over to a brick wall. When he approaches, she phases into the wall and out of his reach. Tar Baby’s momentum carries him forward anyway, and he becomes hopelessly adhered to the brick surface. Mass-Master commends Kitty’s trick; he could probably pull a stunt like that using his powers too, he says.
Nightcrawler asks Erg why he hates Leech so much. Why does he think, he asks Nightcrawler? Leech blocks their powers and drives them crazy. They have to get rid of him and Annalee somehow, even if it means kidnapping children and rubbing out a few X-Men in the process. Erg then fires a jolt of electricity right at Nightcrawler. Surprisingly, Energizer catches it in mid-air. Erg is astounded; how did she learn that trick so quickly? Before she can answer, Nightcrawler teleports right alongside the Morlock and punches him in the cheek.
At this point, Piper brings out his flute and plays a tune that summons a swarm of bats. They attack the X-Men and Power Pack en masse. Alex and Katie knew he could summon alligators, but they had no idea his powers worked on other animals as well! While the terrified heroes struggle to fight off their flurry of attackers, Mass-Master, in his vapor form, approaches Piper from above, and at the last minute, condenses himself and collides with the Morlock’s flute. It falls out of his hands.
Finally, Lightspeed returns with Leech from their jaunt into the tunnels. She tells everyone to stop fighting. Having just learned the whole story from Leech, she doesn’t think they need to fight each other anymore. “No kidding! Our powers just cut out!” Jack Power quips. Annalee, meanwhile, greets Julie’s return with open arms. She tells her little angel to come to her mama. Julie insists Annalee isn’t her mama. She notices Nightcrawler and Shadowcat standing with the Morlocks and winces at the sight of them—specifically at Nightcrawler.
Leech insists they are friends. If he says so, Julie concedes. Moving on, she explains that she and Leech got to talking in the tunnels and learned what’s going on with Annalee. Annalee wanted Leech to help her feel better, but Leech didn’t know that meant kidnapping other children! “Bad. Wrong,” Leech says. Not only is that against Morlock rules, but the Power siblings have parents who would miss them as well, Julie says. Doesn’t Annalee see? If Power Pack stays with the Morlocks, their mother and father would feel just a lonely as Annalee!
Julie offers Annalee a proposal: if she really wants someone to love, why not adopt Leech? He needs lots of love! “No!” Annalee shouts. “Leech is ugly! Annalee wants her pretty darlings!” Leech turns his head and cries, while the kitten in his arms laps up his tears. Power Pack cannot believe Annalee could say something so cruel… even if it is true. It gives Julie an idea, however. When Leech approaches the Power siblings to give them back their kitten, Julie insists he keep it. He loves that kitten, she says. “And unlike some people, he’ll love you back!” Jack adds.
Shortly thereafter, Nightcrawler informs Piper he is obligated to tell their leader, Callisto, of what occurred today. Piper begs for mercy. Annalee was so unhappy! he says. Her misery infected and influenced their judgment! Surely Nightcrawler understands. Kitty sympathizes; if they tell Callisto, she might expel them from the Morlocks. Who knows what they might do then? Kurt takes all this to heart and comes up with a compromise. He decides to write Storm a letter and have her break the news to Callisto. After all, the Drain Dwellers broke Storm’s law, not Callisto’s.
As the X-Men leave with Power Pack, the young kids thank them for the rescue. After witnessing Nightcrawler and Kitty’s finesse in battle, they realize they need some formal training in their powers. Kitty tells them they live at a school that trains them specifically for that purpose. She asks Power Pack if they too would like to attend. As much as they would love too, they just can’t, Katie Power says. Their parents do not know about their superpowers. If they confessed, they would spoil everything! After thanking the X-Men for walking them home, the kids combine their powers and lift off into the sky to complete their journey. As they leave, Kurt asks if they’re mutants. “Nah! We got our powers from an alien named Whitey so we could save the world,” Lightspeed explains.
Kitty watches them go in awe. She wasn’t much older than Gee when she found out she had superpowers. That feels like ages ago, she adds. She suddenly feels old just talking about it, especially in comparison to Energizer, who can’t be much older than kindergarten-age. She supposes the X-Men should do something to help Power Pack, but Kurt thinks they should let it go for now. They can tell Professor X in the morning. “Why not?” Kitty agrees. “How much trouble can they get into before morning?”
Later, Power Pack arrives home via their bedroom window. They change out of their costumes and get ready for bed. Although Jack feels bad for Annalee, he’s glad they don’t have to stay with her. Suddenly, Alex remembers the time Carmody tried to kill them because he mistakenly thought they were mutants. “If all mutants were like Morlocks,” Julie says, “I can see why people would be scared!” She wishes her brothers goodnight and heads to her bedroom with Katie. Along the way, Katie supposes that looks can be deceiving. Nightcrawler, after all, looked kind of like a monster, but he and Shadowcat were so nice. Julie agrees; her dragon was neat too!
As the two sisters climb into bed, Katie admits she feels scared. It looks stormy outside, she says. She asks if she can sleep in her big sister’s bed. Sure, Julie says—just as long as she promises not to disintegrate the bed. As they fall asleep, Julie says that although the Morlocks were scary, they were people too, with human feelings. At least the Morlocks have each other. “Probably it’s better to be horrible together, than horrible all alone!” she says. “And now Leech has someone to love, too, even if it is only a cat!”
The girls fall fast asleep. They accidentally leave the light on, however. Outside, a familiar figure—Annalee—looks up at their bedroom window. She tells her little pretties not to worry; their momma is watching over them, and soon, they will be together forever.