‘AVENGERS ASSEMBLE!’ shouts Clint Barton a.k.a. the Avenger known as Hawkeye, leader of the new West Coast branch of Earth’s Mightiest Heroes as their Quinjet is attacked by their deadly enemy Ultron-12 and is robot hordes. Ultron exclaims to his “son” the Vision, that his ally wants him dead, and while the Black Talon failed to deliver, Ultron thinks that it is because he doesn’t know the Vision like he does. The Vision tells Ultron that he may thinks he knows him, but that he doesn’t really. Ton Stark in his armor as Iron Man, declares that Ultron doesn’t know them very well if he doesn’t think they won’t stop him.
Ultron punches Iron Man and reminds him that he has beaten him once before. ‘That’s right, so now you owe me one!’ replies Iron Man as he smashes Ultron into the side of the Quinjet. The Vision remarks that Ultron may have created him, but from borrowed parts, as Green Grant Nelson, better known as Tigra, points out that the suction from the hole is incredible. Wanda Maximoff a.k.a. the mighty Scarlet Witch tells Tigra to hold on, while Wanda’s husband, the Vision, says to Ultron that his body was from the android Human Torch, and his mind from Simon Williams - the youngest son of Martha Williams. ‘I’m no relation to you!’ he shouts.
Wanda moves closer to the hole before they all pass out from lack of oxygen, and seeing a large seat, Wanda knows that it is unlikely to withstand the pressure, so she uses her mutant abilities to cast it to the hole, and make the improbable become probable so that the seat stays and blocks the hole. Hawkeye calls to Iron Man, telling him to leave Ultron as Ultron’s robots are tearing off the wing. On a computer console, Hawkeye’s wife Bobbi Morse-Barton a.k.a. Mockingbird, who is back at the West Coast Avengers Compound in Palos Verdes asks Clint what is going on.
Wanda helps Tigra up, but Greer is concerned over the fact that she is very little use against the robots as her claws are designed for flesh. Clint wonders if he can blow the robots off the wing with peak velocity, while Iron Man tells the Vision to stay with Ultron, and Clint tells Mockingbird that he cannot talk anymore as he has to fly this thing. Iron Man flies out of a hatch and thinks to himself that he has to move fast, but that he likes how the new armor holds up and feels also. Seeing one of the robots he has previously fought, Tony flies over to it and asks somewhat sarcastically if their shoulder point is still their weak point. Easily tearing the robot apart, he remarks ‘Guess so’.
Back inside the Quinjet, Ultron remarks that the Vision is concerned too much with his past, as it affects his concern for his future. Tigra stands around near Ultron and thinks to herself that she could never fight him, but what of his flunkies? Ultron boasts that he is Ultron-12 now, and has evolved himself far beyond where he was when he had the Vision built. Tigra puts on a breathing mask and exit’s the Quinjet through the hatch as the Vision remarks that his future lies in his past - in the humanity his mind was born into. ‘Your future has less than an hour to run!’ Ultron declares.
On the wing, the ship jolts and Tigra is knocked over. Clinging to the wing she thinks to herself that her claws may bot slash metal, but is thankful that they can hook onto it. ‘Boy, could I use a tail, right now!’ she thinks to herself before calling out to the robot - ‘Hey, tall stark and handmade! Wanna fall for me?’ she jokes as she pushes the robot off the wing of the Quinjet. Tigra kicks another of the robots using her cat-like strength and thinks to herself that it is not for nothing that she is the embodiment of the Cat People’s finest warrior. But watching Iron Man literally smash through another of the robots, Greer knows that she would love to have power like that - or else, be free of her Tigra persona forever!
Inside the Quinjet, the Vision attempts to phase a hand into Ultron, but Ultron tells him he can try, but will not succeed, as he has evolved himself past that weakness. The Scarlet Witch turns to Ultron and informs him that when he fights her husband, he must also face her, and casting a spell at Ultron, Wanda declares that nothing evolves past disruptions of probability. With the hex cast, the Vision is able to plunge his hand into Ultron’s chest, then ripping off one of Ultron’s arms, he asks him ‘How long is your future now?’ ‘My arm!’ exclaims Ultron, to which Hawkeye fires an arrow at Ultron’s exposed wiring.
Ultron screams as the arrow hits him, and he rushes past the Scarlet Witch, heading for the seat Wanda had cast into the side of the ship. ‘NO!’ exclaims Wanda as Ultron jumps at the seat, forcing it out into the air, and he flies out after it, with Wanda being sucked out after him. Hawkeye tries to control the ship, while the Vision races over to where Wanda is clinging for dear life to the side of the ship, and reaching his wife, the Vision pulls her inside.
Outside, Ultron flies around and is annoyed when he sees Iron Man speed down towards him. Iron Man knows he has to be careful because the Quinjet is in so close proximity to him, but manages to grab Ultron, however they both crash into the side of the Quinjet. Inside, Hawkeye thinks to himself that they are out of control, so he tries his best to steer the ship, but knows that if he doesn’t take his hand off the controls to get some oxygen soon, then he will black out.
Luckily for Clint, his dear friend Wanda places an oxygen mask on him. The Vision asks Hawkeye if he can pull it out, but Clint replies ‘Don’t bet the rent money!’, before explaining that he threw them into high gear to try and blow the robots away, but now they have overshot the plains and are headed for the Rockies up in front of them. The Vision assures Clint that of all people, he will be able to save them, while one the wing of the jet, Tigra continues to cling on. Iron Man hovers beside the ship and thinks to himself that now that Ultron has done his dirty work, he has gone, but although Tony also knows that his jet thrusters could easily enable him to catch up to Ultron, he knows he must stay with his friends, for although he cannot pull them out of the dive that the jet is in, he can give the ship back some balance.
Tony uses his armor-strength to balance the ship, and inside, Clint exclaims that he has got control back, but points out that they are heading straight for that deadly peak up ahead. Suddenly, Wanda exclaims that it won’t give them any trouble, and she uses her hex powers to simply make the top of the peak disappear. Many of the Avengers do one thing very well, and that earns them great publicity. Hawkeye on the other hand doesn’t get that kind of press - because he does many things well!
In the end, the Avengers crash - but if it was anyone but Hawkeye piloting the plane, they would be dead. If that’s worth much. Finally, the Quinjet comes to a halt in some woods, and Ultron circles it as he radios into the Grim Reaper, boasting that he has succeeded in capturing the Vision and his companions, but that he cannot transport them all back, so he gives the Reaper his coordinates.
Sometime later, the darkness begins to lift for those who were knocked unconscious, and they use their slow return to awareness to play possum. They listen and hear booming echoes and the sound of water dripping and know before they open their eyes that they are in a cave. The five heroes find themselves in similar energy globes to the one that Wonder Man a.k.a. Simon Williams and Hank Pym are trapped in - and standing also in the cave along with Ultron, are the Grim Reaper, Nekra, the Black Talon, the third Goliath, Man-Ape, and a horde of zombies - as well as a near-naked man who resembles Simon Williams long before he was transformed into Wonder Man.
The mighty Grim Reaper welcomes the Vision to his home away from home - ‘And your eternal tomb!’ The Grim Reaper declares that, at last, he has everything he wants - the plastic mockery of his brother, the one with the stolen mind - and the mutant monster whose muscles bulge and eyes burn with ionic energy all forced upon his brothers body. The Grim Reaper motions to the near-naked man and announces that this is what Simon Williams looks like - ‘This unliving zombie shows what Simon should be!’
The Grim Reaper reveals that he spent many years searching for a body whose resemblance to Simon’s was so marked that only minor plastic surgery would be needed. ‘That, and a mind!’ he adds, explaining that the Vision and Wonder Man together have his brother locked inside them and they both have Simon Williams’ soul, which he proposes to strain from them. Wonder Man calls to the Vision, explaining that the Grim Reaper wants to transfer their minds to a Ultron’s computer, then compare them, one against the other, and then, everything that one of them knows but the other doesn’t, gets discarded, while what is common between them remains as the “real” Simon.
The Vision understands, and supposes that the Black Talon will then use his voodoo abilities to transfer that mind into the zombie Simon Williams. The Vision turns to Eric Williams - the Grim Reaper - and remarks that it serves his purpose wonderfully, but that his purpose is as skewed as ever. ‘Do not call me Eric, you overgrown doll! I am not on those terms with you!’ the Grim Reaper warns the Vision, who suddenly replies ‘Oh, but you are’ and informs the Reaper that he has just met their mother, Martha Williams.
The Vision remarks that he has just found, for the first time, a human parent, to go with his robotic one. Wonder Man wonders what the Vision is talking about - if he is really talking about his mother, before the Vision declares that he is no Simon Williams, nor does he need to be, ‘I am the Vision - that’s enough! But I am related to you, Eric!’ ‘NOOO!’ screams the Grim Reaper, thrusting his scythe-hand around, the Grim Reaper declares that the Vision doesn’t relate to him, and warns him not to mess around with his mother, ‘You’re a piece of plastic scum!’ Wonder Man thinks to himself that he has never thought that Simon Williams’ mother is his mother - even though he is Simon Williams, whatever Eric says about him. But then, so is the Vision sort of. ‘I’m Simon mutated and he is Simon transplanted. Wonder Man looks at the Vision and realizes that the Vision is not afraid of death. He wonders if that is because the Vision is a synthezoid, but decides against it, because he can hear it in the Vision’s voice when he talks about their mother - he is human inside - Simon is in there. ‘I am in there! Wonder Man realizes, remarking to himself that he has always known it - they are more than brothers, they are twins.
Simon admits that he didn’t want to see it - because he thought of the Vision as inferior, limited, a mechanical replica of a real man. Wonder Man saw the Vision’s reserved tendencies, metallic voice, pinpoint eyes and just said “I’m not in there! Not really, that’s just a simulation!”. Wonder Man thinks all of a sudden that he himself is the inferior one. Noticing Simon’s sudden disparate stance, his “cell mate” Hank Pym thinks that what he tried to tell Wonder Man is sinking in. Hank steps closer to Simon and tells him to “be a man”.
In his own “cell”, Hawkeye realizes that although the Grim Reaper is concentrating on Simon and the Vision, the rest of the Avengers are the next course, for he hates all Avengers for supposedly killing Simon and starting this whole thing off. Iron Man wonders why the Grim Reaper doesn’t face up to what he is - for it was Eric, not Simon who embezzled their company’s money. Tigra looks at Simon and thinks to herself that he looks really haggard - much worse than Hank - and she wonders what their enemies have been doing to them. Wanda wonders if the Grim Reaper has made a mistake, for after the Vision nearly lost is consciousness to the Isaac Computer, he removed the control crystal which allowed such takeovers.
The Grim Reaper turns to Ultron and declares that it is time to get on with it. Ultron informs his ally that he has a request, and asks if he can take Wonder Man’s mind first, for he wants the Vision to watch what happens to his “human side”. The Grim Reaper replies that he doesn’t see why not, to which Ultron reminds the Grim Reaper that he did capture Wonder Man as well as the Vision. Ultron taps a switch at a console and tells Wonder Man to come along, but that he will cripple him as readily as the energy cage would have if he attempts to resist.
As Simon exit’s the energy cell, Hawkeye thinks to himself ‘Do something, Simon!’ Tigra and Hank Pym also think the same thing, while Wonder Man tells Eric that he will not see him grovel, and that whatever he does to him, he will be lucky to be rid of him. Hank thinks that Simon is fighting his fear, but not his enemies. Simon turns to the Vision and tells him that he is glad he got to meet their mother, and admits he never mentioned her to him because he wanted her all to himself. ‘Hey, we don’t need nobility here!’ Hawkeye thinks to himself, before Wonder Man tells the Vision that he knows their mother is glad to have had both of them. ‘She is, Simon. She is’ the Vision remarks, before the Grim Reaper orders his associates to strap Wonder Man down, as he wants an end to this profanity.
Wonder Man turns to the Grim Reaper and admits that he has thought about how awful it would be if he died - and how awful it would be if the Grim Reaper died. But now, he is thinking about what their deaths would mean to her. With that, Simon punches Eric in the face, knocking him back, to the cheers of Tigra. Wonder Man declares that it takes strength to lay down your life for your friends, but that it takes more to stand up and live!
The Grim Reaper calls to Man-Ape and Goliath, ordering them to help him, as Wonder Man cannot overcome all of them, but at that moment, Mockingbird makes a startling appearance and dropping down from the ceiling, she kicks the Grim Reaper over. As she hit’s the master control lever to free her friends, Bobbi informs her husband Clint that the Quinjet’s radio was on all the way down, so as a former S.H.I.E.L.D. agent, she had no trouble getting her former affiliates to run a fix on the Quinjet’s location.
After Bobbi remarks that the hard part was finding out where their enemies had taken everyone after that, Clint tells Bobbi to reminds him to tell her how much he loves her later. Tossing her husband his bow, Bobbi tells him he can count on it. The Grim Reaper calls the Avengers “overweening fools” as he points out that they are still vastly outnumbered thanks to the Black Talon and his zombies. However, Eric Williams turns and sees both the Man-Ape and Black Talon, along with the zombies, fleeing down a side tunnel. The Grim Reaper calls out to them, ordering them to come back, before Hank Pym tells the Reaper that he thinks the Man-Ape and Black Talon didn’t like his views on Civil Rights.
Hawkeye boasts that someone is indeed outnumbered here, but that it isn’t the Avengers. The arrogant Ultron boasts that he alone is worth them all, when Wonder Man and Iron Man smash into him from either side. Seeing that Hawkeye has the Grim Reaper occupied, the Vision suggests to Wanda that they take on Goliath, which they do, while Tigra leaps at Nekra and remarks ‘You may come from the jungle, Nekra - but you’ve never met a cat like me!’ Hank Pym also attacks Nekra, mumbling that if anyone thinks he is going to sit on the sidelines after the pep talk he gave Simon, then they are mistaken.
But, in the heat of battle, the odds can change in an instant - and indeed they do, as the Grim Reaper sends a bolt of energy up to the roof of the cave, causing part of it to fall down upon Hank, Tigra and even his lover Nekra. Tigra leaps out of the way, rescuing Hank as she does so, only for Nekra to come up behind them and grab them. The Grim Reaper exclaims that it is over, as the Vision and Wonder Man have escaped him. Nekra reminds her lover that he still needs to escape them, and beckons him to come along with her.
Tigra exclaims that she will catch them, but the Vision tells her to stop, announcing that the Grim Reaper belongs to he and Simon. Wanda remarks that she will go with them, but the Vision tells her not to, explaining to her that they are together in everything else, but that this is something he has to do with his brother. Iron Man assures Simon and the Vision that he and the others can take on Ultron and Goliath.
So as the battle rages on behind them, Wonder Man and the Vision embark on a very important chase. Entering the dark tunnels, Wonder Man tells the Vision to be careful, as the trail turns almost at once. He adds that he doesn’t know how, but he can see it. The Vision supposes that the ionic change in Wonder Man’s eyes has made them similar to his own electronic ones which respond to wavelengths beyond visible light. The Vision explains that, in other words, he can also see the change in trail.
Wonder Man asks the Vision which way he thinks they should go, but the Vision replies that he doesn’t know. This surprises Simon, so the Vision explains that his hearing is only slightly above normal human hearing. ‘Oh, well, let me listen’ Simon remarks, and after a moment, Simon reveals that the Grim Reaper and the Albino woman have split up - and their brother went up ahead of them. The Vision tells Simon to lead on, but Simon asks the Vision if he doesn’t want them to split up also.
‘No!’ exclaims the Vision, before they continue along the tunnel. Shortly, Simon apologizes to the Vision for taking so long to get going back there. The Vision replies that it doesn’t matter, not between the two of them. The Vision extends a hand to Simon and declares that he knows what it means for them to be brothers now. Simon ignores the Vision’s hand, instead, he hugs him. The Vision hugs back, and afterwards, Simon admits to the Vision that he is scared. ‘I mean, I’m mad, and I’m happy, because of you - but I’m afraid of the dark - afraid of what might happen!’
The Vision tells his brother that he knows he will not let either of them down, for that is the most important point - that they stick up for each other. The Vision then assures Simon that everyone is afraid sometimes. ‘You? You feel fear?’ Simon asks. The Vision replies that he feels everything, and while he may react in his own unique manner, he feels it all. Simon remarks that he feels like he wants to get his hands on their other brother. ‘Lets do that and see how it goes!’ he exclaims, before revealing that he has got a plan.
Nearby, high in the cave where the bats come to roost, the Grim Reaper walks along a narrow ledge and thinks to himself that he cannot hear any sound of pursuit, so Ultron must be giving his all for him. ‘As a stupid machine should!’ Eric thinks to himself. Eric thinks to himself that when they do come, he hopes they chase him and not Nekra - ‘That woman, WOW!’ A bat flies past the Grim Reaper as he decides that they will never catch him here, and he can hide until it is safe to leave.
But suddenly, he fears footsteps, someone heavy - ‘Probably that so-called “Wonder Man”!’ he thinks. Noticing several large openings in the side of the cavern, the Grim Reaper thinks that there are plenty of places to hide, but as he runs for one of those places, he crashes into the Vision. Wonder Man joins his brothers and declares that the Williams boys are together again. ‘You think you’re on a roll, don’t you? Well, laugh it up, freak - or kill me up here where it’s dark and no one will know - because I will kill you in the end if you don’t!’ the Grim Reaper declares.
The Vision asks him why, and tells him to face facts - whatever he think happened to Simon after he became Wonder Man, ‘You are the one who drove him to that point! You stole the money that put him in court and drove his company under. The Grim Reaper admits that he stole the money, when suddenly Simon tells him to stuff it. ‘You didn’t steal the money - I did!’ The Vision expresses his confusion, but the Grim Reaper tells him not to listen to Wonder Man, as he is lying - he is insane.
The Grim Reaper turns to Wonder Man and asks him to ask the woman he calls his “mother”, as she will tell him the truth. ‘Simon didn’t really do it’. Wonder Man declares that their mother doesn’t know the truth, and admits that he is not a saint, but that he cannot let Eric keep calling him one, because it is not true. ‘You know I stole the money because you know you didn’t! But you take the blame so you can make me something I’m not!’ Simon tells his brother. The Grim Reaper exclaims that it isn’t true, as Simon was perfect, and although he did his best to corrupt him, he never could.
Simon exclaims that all his life people told him how good he was - especially compared to Eric, but that he wasn’t good enough in the end. He points out that he wasn’t good enough to keep the company alive, wasn’t good enough to turn Zemo down and wasn’t good enough not to steal. ‘The only good thing I ever did - because I chose is over evil - was to die for the Avengers!’ Wonder Man remarks that when he came back, he tried to tell everyone how strange - how wrong - it felt to be cast as a hero, yet they just patted him on the back and smiled.
‘”You’re good” They said! “You’re smart! You’re strong! You’re handsome! And you’re an Avenger! So it will all work out”!’ Eric listens as Simon says that it was because he never told them the truth - that he was guilty! He tells Eric that everyone thought it was he who stole the money - even if the official verdict was otherwise, so after a while, he even stopped thinking about it. Simon remarks that he started looking, not at his disease, but at the symptoms - like the fear that retribution might be coming him out of the dark.
Simon declares that his guilt just festered, poisoning him - until tonight when he finally saw the Vision clearly - and saw what Simon Williams might have been if he hadn’t known what he’d done before he became Wonder Man and died. ‘Until I saw - my better twin!’ The Grim Reaper looks at the Vision as Simon declares that he know cleanses himself, he must let go and try to change, before exclaiming that nobody really knows what happened, except he and his brother. ‘If you really know!’ he adds.
The Grim Reaper looks at Simon who tells him that he understands he must have loved him to do so much for his memory. Eric replies that he did love Simon, that he was his only brother and swore he would get the people who killed him - ‘And then I would have killed you!’ Eric declares as he shoves past Simon and the Vision and begins to run along the ledge. Simon calls to Eric, telling him not to run, as Eric calls back that they are the ones who are twins, and it is he who is different. Suddenly, Eric slips on the ledge, and he falls down into the darkened enormous pit beneath them. Simon and the Vision call out to their brother, but they only answer is the sound oh him hitting the bottom - hard.
Shortly, Tigra and Iron Man tie Goliath up, while Simon tells Hank that he was right about what he said - that he should stand on his own two feet. Hank tells Simon not to give him any credit, as he stood on his own two feet, adding that in the end, every man is really alone. Glancing at the Vision, Simon tells Hank that he is wrong about that.
The Vision informs Wanda that he searched much of the crevasse, but that it was a mile deep and several miles long, so Eric’s body may never be found, and Nekra had long since vanished, he then asks of Ultron. Wanda reveals that he escaped, explaining that Tigra kicked him into the computer - an honest mistake, but he used it to augment his power and breakaway.
Wanda and the Vision exit the cave, with the Vision remarking that it is a problem for another day, for right now he feels as near to problem free as he ever has, adding that in one day he has found both a brother and a mother. Wanda tells the Vision that she knows what he means, and reminds him of when she first met her real father. The Vision tells Wanda that this may seem a strange place to say what he is about to say, but explains that with everything that has happened, he has been thinking - thinking about death and about life - about his mother and her sons. ‘What would you say to our, uh…having a baby?’ Wanda doesn’t say anything.