The X-Men and their newest addition Aaron, the future Machine Man, find themselves surrounded by Lava Man. Beast carefully notifies Cerebro that they have made contact with the Lava Men. He is attempting to show them that they mean no ill will. Making placating gestures, Hank welcomes them to the surface world, and asks why they came here. Bobby asks very slowly if they need some water. Hank tells him to shut up.
The Lava Men confer with each other in their own language. Triumphantly, Beast runs around to tell the others he thinks he is getting through. The next moment, one of the Lava Men hits him full force.
Cyclops orders everybody to get clear and fires a full optic blast at the attacker, taking his head and that of one other clean off. Uh, dang, Scott just killed these dudes, Bobby remarks. The next moment, the two heads act on their own accord and bites Bobby in one arm and leg respectively. Hank tries to tear the head off, but quickly removes his hand in pain – they are hot!
Jean telekinetically removes them, remarking they can’t burn her thoughts. Sounds like poetry, Bobby suggests.
Taking out two more Lava Men, Jean shouts they can get off her case. As even more appear from underground, Iceman tries to create an ice shield that is instantly melted down.
Where is Aaron? Jean asks, and Hank remarks he appears to be carefully recording their demise for posterity. Aaron, he shouts “little help!” as Bobby would say.
Aaron just stares down at them without a word.
Xavier mentally contacts the X-Men and sees they have found the Lava Men. In truth, it was the other way round, Hank points out as the four of them keep on fighting. And they’re not too impressed with their mutant powers, Jean adds.
Xavier finds he cannot affect their minds. You know what else can’t affect them? Bobby bitches, as he evades a lava blast. Aaron! Or rather, he won’t.
Xavier informs Doctor Stack about Aaron’s inaction. Stack contacts Aaron, giving him order: “Empty cache command nine, prompt zero G.” Aaron finally reacts, landing and ordering the Lava Men to cease hostile maneuvers or he will retaliate with maximum force. They grab his arms. Cyclops offers to clear out a path for Aaron. Unnecessary, the robot tells him. His head flies off as one Lava Man hits him. What is it with all the detaching heads today? Bobby complains.
“Full limb extension,” the head orders and his arms extend, smashing through two lava monster. Revolution the head orders, and his body spins fast, pureeing the Lava Men.
Okay… not bad, Jean admits unsure as Aaron reattaches his head. Hank points out the threat isn’t over. They are going back under. Yeah, sneak away, stupid little rocks! Bobby shouts. You can’t handle it. Thanks to their destructive robot pal. Cyclops warns him they can reform and attack again. And their destructive robot pal can just puree them again, Bobby retorts.
A lava head appears from the ground, saying something in their language. Bobby screams startled, then tosses a snowball at it. Creating an ice-paddle, he beats the ground, even though the face is long gone.
Extending sensors from his fingers, Aaron examines the ground. They did not continue downward. Possibly segmentation for that long is difficult. They would likely lose consciousness, Hank agrees. Extending a sensor from his head, Aaron scans and finds which way they migrated to.
A little later, they find tracks. Aaron explains that they reassembled their bodies at this point and walked from here. Cyclops commends him. He is a real marvel of engineering. Aaron gives him an unreadable look.
Elsewhere, Dr. Stack is horrified by what he has just learned. He just checked his messages, he explains to Xavier. Something has gone horribly wrong at the X-lab.
Nearby, the X-Men follow Aaron who is tracking the Lava Men. He leads them to a cave. This is great, Jean remarks. Let’s go down into where they’re from. Give them more of an advantage. If Jean’s being sarcastic, he agrees, Bobby states. If not, he doesn’t. Cyclops decides that they have to investigate more. They know the Lava Men aren’t behind them, and if it gets hairy, the X-Men are faster.
As Hank passes out torches, he remarks that this was a dormant lava tube. Perhaps they opened into it from a live one. Aaron detects a heat source one kilometer in.
Xavier mentally contacts the X-Men and warns them to say nothing and listen. Dr. Stack has received word that other X-series robots have become erratic and dangerous. Has Aaron been behaving oddly? What exactly does “odd” mean with Aaron? Scott asks. Xavier explains that the problem androids went awry very quickly and unexpectedly. He suggests they wrap up their inspection of this tunnel and return soon, so Dr. Stack can examine him.
Bobby hesitatingly point out he thinks Aaron’s okay. He hasn’t noticed anything. It took several heavily armed troops to put down the rogue robots, Xavier warns them. Others have been shut down temporarily. He will contact them again soon. Hopefully, the problem is an isolated on and the android with them will perform fine. Okay, now they know they are doomed, Jean sends back.
Aaron suddenly turns his head around 180 degrees, asking a question: is their goal to suppress the lava creatures and ban them from the surface? No, Cyclops replies. It was a fact-finding mission until they attacked the X-Men. They are clearly hostile, so they may have to seal the Lava Men off, unless they can come to some arrangement. Which is unlikely, since they don’t speak rock talk, Bobby points out.
Walking on while keeping his head at this unnatural angle, Aaron presses. What if the Lava Men were here first? Perhaps humans are infringing on their territory. He’s being pretty philosophical about it for a military guy, Jean observes. For a piece of military hardware? Aaron asks. Is he exceeding his design parameters? That’s not what she said! Jean exclaims. Hank hisses at her not to provoke their guest member…
“Look out!” he suddenly shouts as Aaron is attacked by a Lava Man. Aaron screams that his sensors have failed him. Other Lava Men come through the walls. Cyclops orders everyone to get down, so he can shoot freely. While he fires, Jean observes that they must have replenished themselves in a lava flow. They seem stronger. She doesn’t even manage to telekinetically pry them off Aaron.
Iceman tries to make them brittle by icing them up. Indeed, Aaron can now pry himself loose, but in the process loses his faceplate while doing so, revealing a skull-like electronic visage underneath.
Cyclops praises Bobby while cutting a swath through the Lava Men. While the X-Men begin to gain the upper hand, Aaron stares at his face mirrored in the glaciers.
The Lava Men retreat. Cyclops suggests they seal off this cavern behind them. He asks Aaron to step back, so he can close the tunnel off, but Aaron is transfixed by his reflection. Suddenly, he screams: Give back my humanity!
Chuck called that one, Iceman mutters. Hank remarks he feared that Aaron was having identity issues. Artificial life theorists often say that making androids think like humans will be problematic. To think of yourself as human and be reminded that you’re clearly not…. People have enough trouble with cognitive dissonance. Computers just don’t do it at all.
Aaron wildly fires and runs after the Lava Men. The X-Men follow to see him madly grappling with the Lava Men in a pit of molten magma.
It’s so hot that Iceman finds he can only make steam. Jean cannot lift Aaron either with all the Lava Men piling up on him. Aaron shouts that they cannot disassemble him. He is no mere machine!
The X-Men helplessly watch as the Lava beings tear him apart. He is a man! Aaron shouts. As Aaron is submerged, Jean can only save the upper part of his skull, a small part with the letters “X-50”.
Cyclops orders the team to fall back and closes the tube off behind them with his optic blast. “Goodbye Aaron,” Beast states somberly.
Later, the team meets the professor and Doctor Stack and informs them of what happened. Hank apologizes for not finding out what made the Lava Men come to the surface. The subterranean world has many societies and dangers, Xavier muses. It could be anything. He will alert the Fantastic Four and the Avengers to the possibility of their return.
Jean carefully hands Stack the part of Aaron’s skull she saved. Stack thanks her enthusiastically. It’s Aaron’s neural engine. In his short time among them he absorbed much about being human and now all that won’t be lost. He is sure the army will put remote destructs in the X-series androids now. To them, the androids are nothing more than weapons. His failing is that to him the android is completely human, which is also not true. He will remember that in the next model. He will teach him that it is possible to be a different kind of being. Still a life form, but not just a man. And Stack begins his construction of X-51.
Jean sits alone in the living room, moping. When Scott asks her what’s wrong, it becomes clear that Jean is missing Warren. Scott sits down next to her thinking, then he has an idea. He begins narrating a past adventure, describing how Angel helped him defeat a frost giant.
Jean begins to crack a smile.
Hank jumps down the stairs in his ubiquitous style. Quickly, he joins them and regales them with the tale of how he and Warren had to fight the Lizard in the Florida Everglades.
Walking past, Bobby catches sight of them. Quickly, he joins them as well, describing how Angel almost got eaten by a monster on Monster Island, much to the amusement o the Moloids.
With a smirk, Jean recalls the romance between Warren and her friend, the Scarlet Witch, as Xavier comes in as well. Bobby quickly adds the end of the affair. How Wanda’s overprotective brother, Quicksilver, got involved and Warren beat him with his wings.
Embarrassed, Jean notices Xavier’s presence.
Xavier recalls how Warren flew out of the classroom straight after an exam and quickly returned with bags full of fresh pizza for everyone.
Scott and Hank recall how Angel got caught like a fly in the web of Spider-Man.
Bobby regales them with the tale how Warren reacted when he and Hank returned Warren’s car full of swamp water after their road trip.
The whole group laughs as they recall more funny events. How Warren stomped the Blob, how he tore away Magneto’s helmet. How he tried to save Jean, who was falling from a Sentinel’s hand, and suddenly only had the lower part of her uniform in his hands.
For a moment, they pause and then glumly recall the present. Angel is gone.