The mutant known as Banshee unleashes his mighty wailing voice as he flies through the mountains of central Europe. The man thinks to himself of how he has been spending weeks searching the mountains and valleys in the area for the group known as Factor Three. He feels that he is very close to their sanctuary and he hopes that he has come in time to prevent them from conquering the Earth.
In the mountains, a cattle herder hears the wail of the Banshee and comments on how mournful and melancholy it sounds, as if a soul was tormented. The shepherd then wonders if this strange sound has any connection to the other weird sounds and happenings that have occurred in this land lately.
Banshee approaches a mountain and, with his ultra-sonic probing, he discovers that the mass before him is actually hollow. He has found what he was looking for. Before Banshee can react any further, he spots a doorway opening, which is more or less a stony slab platform in the middle of the mountain. The wailing mutant realizes that Factor Three has spotted him, much as he feared that they would.
Banshee decides that there is no time for retreating and he must discover what the sinister group wants, as well as what defenses they have. He then spots something standing in the doorway of the mountain. Banshee notices that it is a large mechanical spider that is emitting a low hum. The man decides to get closer to learn more, but it turns out to be a grave error as soon as he nears he is blasted by a paralyzing ray coming from the single eye of the spider-machine. Banshee tries to retaliate with a hyper-sonic howl, but the spider is able to prevent his attack. Realizing he has only one chance to obtain freedom, Banshee throws himself off the ledge and away from the spider’s ray, hoping that he will have enough strength to fly away.
Banshee falls for what seems to feel like an eternity, but the man finds that the luck of the Irish is with him and he is able to muster enough strength to use his sonic powers to fly. The man is still groggy, however, and decides to return to his base, as if he loses consciousness he will surely fall to his death. Banshee barely makes it conscious to the chalet he rented and hurries inside to inform the X-Men of his discovery before it is too late. Now that Factor Three knows that he has found them they will be after him. Inside, Banshee uses the advanced devices given to him by Professor Xavier to find Factor Three to contact the man and warn the X-Men about the spider.
Back at the Xavier Institute, the X-Men are busy analyzing data to help them find out where the kidnapped Professor Xavier is. Iceman tells the group that Angel is returning from his lookout mission and may have news. Cyclops decides that he and Marvel Girl will rendezvous with Angel, and tells Iceman and Beast to stay on Cerebro-watch, as they cannot have a surprise attack by Factor Three again. Marvel Girl wonders where in Europe the group has taken their teacher, but Beast tells the woman not to abandon hope, for they will find Xavier yet.
Outside, Cyclops and Marvel Girl meet Angel, and Cyclops can immediately tell that Angel found nothing. Angel confirms this, but mentions that he did find a small clue. He found traces of a saucer shaped vehicle nearby. Cyclops deduces that the ship must be what Factor Three took Xavier in when they were busy fighting Juggernaut. Marvel Girl, however, reminds the boys that a saucer won’t leave any tracks behind, so they are just as much in the dark as they were before. Suddenly, Iceman calls from the upstairs window and tells the group that they are receiving a call from Banshee. Excited, Cyclops hurries Marvel Girl and Angel back inside.
In his chalet, Banshee sends his message out to the X-Men, but it seems that the attack of the spider has taken its toll. Banshee realizes that the ray attack weakened him more than he realized and that he is blacking out soon. However, he must warn the X-Men. After sending his incomplete message, Banshee slumps to the floor unconscious. Two members of Factor Three enter the chalet and find the man down, glad that they do not have to fight him. They then carry Banshee aboard their Gravo-Disk, so they can report to their master.
In the Gravo-Disk the two report back to their master and announce that their mission is accomplished. The master is pleased and tells himself that he knew that a mutant that was forced to join them would ultimately betray them. However, any threat that Banshee posed is not eliminated. He will send a reconnaissance unit to America to see what the X-Men have learned from Banshee. If the X-Men ever find where they are, Factor Three must be ready to destroy them all.
At the mansion, the X-Men ponder over Banshee’s message, which tells them to beware the spider. Beast suggests that perhaps Banshee was unable to send out his entire message before something happened to him, and Cyclops agrees. Marvel Girl, however, still thinks that the message is some sort of prank, but Angel reminds her that Banshee would never joke around when it concerns Factor Three. Cyclops agrees and tells the team that they must heed the warning.
Meanwhile, nearby the mansion, Peter Parker, the sensational Spider-Man, finds himself riding around on his motorbike through the hillsides of Westchester County. Peter thinks about how the city is a nice place to live, but not to visit. When he needs to relax he is more of a back-to-nature kid. He thinks it is funny how he just winded up in Westchester after hopping onto his bike. It is almost as if fate brought him here. Peter then reminds himself not toe make a big deal. He just got lost. After that last run-in with the Kingpin, maybe getting lost for a weekend is what he needs.
Peter stops by a tree and walks to a stream, with a mill beside it. Peter spots a nice, peaceful hill and pulls over, deciding to do the whole “Thoreau bit” for awhile. He also notices the stream and also declares that he will explore the nearby mill. However, before Peter can reach the stream a large shadow casts itself upon him. Peter wonders if the weatherman is wrong again before looking up into the sky and sees an egg-shaped saucer heading towards him. Has one of his foes discovered his identity as Spider-Man and come to kill him?
Peter ducks into the mill, but notices that the saucer is simply circling around. It may not be after him after all. He sure is turning into a walking, talking persecution complex. Peter wonders what the saucer is after, and what is truly is. The saucer begins to land as Peter realizes that he will find out soon enough. Luckily, he is wearing his Spider-Man outfit underneath his regular clothes.
Peter changes and Spider-Man leaps out and wonders if it is dumb luck that he had his uniform. Perhaps there is no real Peter Parker and that Parker is Spider-Man in disguise. Spider-Man decides to save his identity crisis for later as the saucer is opening. A large metal spider emerges and Spider-Man notices its single eye upon a tentacle. Spider-Man then realizes that he shouldn’t stand around and admire it as his spider-sense is telling him that it is about to attack. Spider-Man leaps out of the way as the spider unleashes a paralyze ray. The hero tells the machine that they may be related, but he doesn’t feel like sticking around for a family feud.
Spider-Man uses his webbing to latch onto the mill’s roof and swings around the building, narrowly avoiding another paralyze ray. The rays seem powerful to Spider-Man, who wonders if the robot can hear him talking and saying his taunts. Spider-Man swings around the corner of the mill and waits on the side. He chooses to wait and observe the robot, which he deduces must be guided by human intelligence. He will not leave until he finds out who operates the machine.
Suddenly, the spider rounds the corner and shoots at the mill, breaking off the piece of the wall that Spider-Man was clinging to. Spider-Man is in awe at the fantastic speed of the spider. He grabs onto the window ledge and enters the mill, swearing that the spider will be sorry he invoked the Spider-Man’s temper. He is going to rip open the machine and see what makes it tick. However, the teenager wishes that he was as confident as he sounds.
At the mansion, Cerebro rings off an alarm and alerts the group of a mutant presence. Iceman is confused, as Cerebro only monitors the surrounding area. Cyclops realizes that the mutant is around the mansion and must be coming for them. Angel swears to make the mutant sorry, while Marvel Girl heads to turn off the alarm so they can check out the location of the mutant. Cyclops tells Jean that it should be easy to find the mutant now that Cerebro is fully functional again. Angel analyzes the data and discovers that the intruder is minutes away. Cyclops warns to team to not assume that only one mutant has been sent by Factor Three. Beast looks at a map and tells the group that the mutant is at old Hawkes Mill, just outside Xavier’ property. Cyclops gathers the boys and tells Marvel Girl to stay behind in case Banshee calls again.
The X-Men pile into a Rolls Royce and drive towards the old Hawkes Mill. Iceman reminds the group that they have to stay in the car, as no one can see that superheroes are in it. Another boy questions why they are always broke, yet can ride in a Rolls Royce. A third wonders if this mutant intruder has anything to do with Banshee’s warning of the spider.
At the mill, the spider machine begins to blast away at the mill. It enters the mill, in which Spider-Man clings to the ceiling, hoping that the machine would enter eventually. He then wonders what he should do with the robot. He swings out of the way as he avoids another ray. The teenager notices that the rays increase in intensity every time and that they may be lethal now. However, he cannot shake up the feeling that he is now involved that something that does not concern him. Of course, now he is involved though he wants to know what the machine is where the machine came from and why it is there.
Spider-Man lands on the back of the spider and grabs its tentacle eye, knowing that the machine cannot maneuver well indoors than it did outdoors. He then holds the eye in a headlock and hopes that his plan works, as he does not have any other ideas after this. As the machine begins to shoot wildly, Spider-Man uses his strength to aim the eye at the body of the machine, and the plan works, as the robot blasts itself. However, the machine explodes, knocking Spider-Man out as well.
Luckily, he regains consciousness in a few minutes and notices that the machine has disintegrated. He is still not sure what happened, but at least his troubles are over. As Spider-Man leaves the mill, the four investigating X-Men arrive, who deduce that the intruder must be in the mill. Suddenly, Beast spots Spider-Man, who notices that the saucer the spider arrived in is gone.
Spider-Man spots the X-Men and wonders what they are doing there. He tells them that he hasn’t seen them since they asked him to join the team. Is it rush week all over again? Cyclops orders the team to stand back until they find out what Spider-Man is doing there. Beast tells the group that Spider-Man must have been the one Banshee warned them about. Spider-Man notices the hostility, as Angel heads straight towards him. Iceman announces that they will find out what happened to Professor X.
Spider-Man leaps back into the mill, not wanting to be hit, much to the chagrin of Angel, who misses his chance to subdue Spider-Man. Not wanting to chase the other alone, Angel heads to the air to wait for his teammates, but Spiderman webs up Angel’s wings, telling him that he should not mess with a man who has tangled with the Vulture. There is an easy out for Angel and that is to call off this nutty attack and to explain what they are doing. Angel tells Spider-Man that he knows exactly why they are there. Spider-Man tells Angel not to say he didn’t warn him.
Spider-Man slams Angel into the water and wonders if the water will make his feathers molt. Suddenly, he dodges an ice ball, meaning Angel’s teammates are nearing. Beast chases Spider-Man up the mill wall and tells Iceman to stop tossing his ice balls for a moment. At the top of the mill, Spider-Man asks Beast if he is willing to give answers. Beast tells the other man that the X-Men will soon have clarity, only if Spider-Man stays put. Spider-Man begins to explain that he was in the area minding his own business. Suddenly, Beast, who was hoping to get close to Spider-Man, leaps at him, but Spider-Man is faster and avoids Beast. Spider-Man tells Beast he is calling up the super-hero fair practice board, though Beast scoffs at this and calls Spider-Man a super-villain.
Beast lands in a windowsill and wonders if they reacted too quickly. Spider-Man has made no overt moves against them, so perhaps he is not the menace. Beast hears a sound behind him. He turns in time to see that Spider-Man has snuck up behind him and kicks him in the back. Spider-Man asks Beast what he expected, for the spider is the underdog in this battle.
In the water, Angel is in awe at thinks that whoever makes Spider-Man’s webbing is a genius. Angel wishes to flap his wings dry, but sees Beast falling into some trees. He flies into the air and saves his teammate, who thanks him despite being able to land on his feet. Up above, Spider-Man wonders why the X-Men are treating him like a bad guy. Who knew that old John Jonah Jameson had subscribers all the way in Westchester?
Iceman sneaks up upon Spider-Man, but Spider-Man notices him and dodges the attack thanks to his spider-sense. Iceman knocks Spider-Man off the roof and though he is disappointed that he did not subdue the man, he knows his teammates below will capture him. Spider-Man tells Iceman that it is only true if he reaches the ground. Spider-Man then shoots webbing to the mill roof and latches on. Below, Cyclops realizes that Spider-Man is stronger than any single one of them, though he is betting his optic blast could end this fight. Cyclops decides to reason with Spider-Man first, and asks them all the stop fighting and to listen.
At the mansion, Marvel Girl hopes that her teammates are well, as she has not heard from them in some time. However, after they left Cerebro went blank. Does this mean the mutant intruder is gone, or is it hiding and waiting to take the X-Men by surprise? Marvel Girl then notices a note among Professor Xavier’s files on Factor Three. He must have meant to show it to them before he was kidnapped. According to the note, the Professor put a special crystal in the headband of the Banshee so they could contact him at any time with a simply frequency adjustment in Cerebro. Marvel Girl hopes that Banshee still wears his band as she adjusts the frequency.
Jean adjusts the frequency and Cerebro sends out a signal to a satellite in space, previously owned by the U.S. government, which bounces the signal a dark cell in the Alps, where Banshee is detained. However, Banshee is unconscious and is unable to hear the call.
At the mill, Spider-Man agrees to listen to the X-Men, but angrily tells them that they have ten seconds to explain why they attacked, otherwise he is returning to the city. Cyclops explains that Spider-Man is the one to dish out the answers. Why he is here and what is his connection to Factor Three. Spider-Man admits he never heard of Factor Three, which angers Angel, who believes that Spider-Man is playing games with them. Spider-Man tells the team that their ten seconds is up and he is returning to the city, which prompts Cyclops to have the team retrieve Spider-Man. Iceman is ready for battle, but Beast reminds him that they just want to interrogate Spider-Man.
Spider-Man ducks into the mill and hopes to escape through the other side, but he is tackled by the Beast. Spider-Man escapes with his spider-strength and sends Beast flying down to the ground. Iceman encases Spider-Man’s feet in ice before the teenager can escape through the adjacent window. Spider-Man swings towards Iceman and hits him with his iced feet, freeing his legs in the process. Spider-Man notices that he is pulling his punches, and so are the X-Men. Angel arrives ready for a rematch, though Spider-Man wonders why Cyclops is. Cyclops announces his presence behind Spider-Man and announces that he has a clear shot of him. He orders Angel to get back so he can take Spider-Man down.
Cyclops unleashes an optic blast, which narrowly misses Angel and cuts Spider-Man’s webbing. Spider-Man is still able to swing out the window, though uncontrollably. He flies out of the window and into the stream outside. Cyclops rushes out and tells his team that Spider-Man has to come up for air soon. Once he does, they will end this. Suddenly, Cyclops’ signal watch goes off. Iceman rejoins the group ready to take down Spider-Man, but Cyclops hushes him, as Marvel Girl is calling them. Beast jokingly points out that she called Cyclops’ frequency only.
Cyclops informs the team that Cerebro detected the mutant leaving after the team left the mansion. Iceman realizes that Spider-Man is one of Factor Three’s non-mutants, like the Ogre, though Cyclops is unsure if that is the case, because why would Cerebro detect a mutant to begin with? Beast realizes that they have made a huge error. Spider-Man emerges from the stream and yells at the X-Men, and even asks them to turn and face him when he shouts threats.
One of the X-Men apologizes to Spider-Man, as he is not the spider menace they were hunting. Spider-Man realizes that he X-Men were after the spider robot he destroyed earlier. He thought it was after him. Iceman does not believe Spider-Man, but Cyclops wonders if a mutant built robot could affect Cerebro the same way a mutant would. Angel is surprised that Spider-Man is telling the truth, though Cyclops admits that the web-head’s story does fill some gaps in their mystery. Beast goes to Spider-Man and offers his hand to help the hero out of the water, but Spider-Man refuses the aid. Beast wants to explain the misunderstanding, but Spider-Man refuses to listen and calls the X-Men crazy.
Cyclops ushers the team back into the car, as they do not have time to spare. Iceman agrees, but wishes that they could fill Spider-Man in on why they are so frantic. Angel reminds Iceman that they cannot without revealing the identity of Professor Xavier. Beast asks his friends if they can leave before the battle starts again. The X-Men drive away, leaving the wet Spider-Man to wonder why the crazy mutants get to drive away in a Rolls-Royce and he is soaked and coming down with a summer cold.
At the mansion, Marvel Girl looks through the Atlas, thinking off how she did not want to tell the others about Banshee’s coordinates until she double-checked where he was. When the team gathers, Marvel Girl announces that she knows almost exactly where Banshee is. Angel wonders how this helps them find Professor X and Factor Three. Marvel Girl explains that Banshee must have been unable to complete his message because he was captured by Factor Three, or worse. Iceman realizes that if they track down Banshee they can find the Professor.
Jean announces that Banshee is in a European mountain range, but none of them can mountain climb and there is no airfield in the area. Cyclops tells Jean that they will get there somehow and save the Professor. Iceman heads to pack and is excited to be able to make his own skis. Cyclops is afraid that Iceman will see a lot more action than skiing.
Cyclops tells Jean that they are going to face their strongest foe on their home territory and, though he’d feel better if she did not come, he cannot make her stay behind. Jean tells him that she does not have the right to stay, as long as the Professor and the Earth are in danger. Marvel Girl then thinks to herself how she will never forget how he wanted to shield her from danger. She will always love him for that, no matter what!