There is darkness all around, before Scott Summers a.k.a. Cyclops appears. 'What have I done? What the hell was I thinking?' he asks.
Ecuador, where two shepherds are watching over a flock of sheep in a clearing in a forest. A mysterious girl watches them from the threes, her skin is pitch black and hair is white. The shepherds suddenly notice her, 'Easy girl' one of them calls out to her in Spanish. The other shepherd points out that she looks half dead, and suggests to the first shepherd that he get her something to drink. No. Just...just...keep him from following me' the woman utters as she touches the shepherd's face, causing his eyes to go blank. She does the same to the other shepherd, and both of them turn, while the woman rushes past them, turning her head, she sees Logan a.k.a. Wolverine, frowning. 'I know that look. If I tell you I've tried to talk a thousand men outta the mistake you're getting ready to make... I know I'm low' Wolverine remarks, before asking the men if there is any way he can convince them to step aside and let him catch the very bad girl.
The men respond by clenching their fists and rushing towards Wolverine, who quickly tosses one aside, while the other leaps at him. Wolverine grabs the shepherd's fist, and slams his own fist into the man's face. Both men drop to the ground, easily defeated, while Wolverine mutters 'Now... where did you go?' as he rushes off into the forest after the mysterious woman.
Later, Wolverine continues to trudge through the forest, sniffing the air, he tracks the woman by her scent 'Damn it...' he mutters, while the woman enters a large circular vault-like door, she looks back over her shoulder, and the door closes behind her. 'I'm too late' Logan remarks, before tapping his earpiece, 'You there?' he asks. 'I can hear you. Go ahead' Cyclops's voice responds. Standing in front of the circular door, which is connected to old ruins with a large Sentinel connected to them, Logan tells Cyclops that he is sorry, but Serafina slipped inside the Vault before he could get to her. 'You want me to cut my way -' Logan begins, but Scott tells not to, as that won't help with the temporal problem, and they need him back on Krakoa. 'We'll have to think of another way in' Cyclops suggests.
Inside the Vault, Serafina is surrounded by a pink glow as she connects to the world inside. A breach has been detected, so Serafina scans for any contagion, but discovers the Vault clean. The Vault then welcomes Serafina and instructs her to proceed to the city, as a glow appears before her.
Later, on Krakoa, the sun shines down over the mutant nation, as Wolverine, Cyclops, Professor X, Ororo Munroe a.k.a. Storm and Hisako Ichiki a.k.a. Armor gather before three mutants who are about to go on a mission. Storm tells them that they need to remember that time flows differently in the Vault. Cyclops explains to them that the idea behind it is essentially the same as the world – that out here in the real world, time moves at its normal pace, but in the Vault, it is accelerated. Cyclops adds that the difference between the two is that the world is evolutionarily based, while the Vault, however, is something else entirely – human adaptation along technological lines, not evolutionary. 'Sounds like a problem in search of a solution Everett Thomas a.k.a. Synch replies as he stands with Laura Kinney a.k.a. X-23 and Armando Munoz a.k.a. Darwin.
Xavier tells everyone to listen to him, that he cannot stress this enough – the Children of the Vault represent the single greatest existential threat to mutantdom – and they know nothing about them, not really. Cyclops explains that they are sending a team inside – and want the three of them to go. Cyclops informs Darwin that they believe his adaptive powers make him uniquely prepared to evaluate both the atemporal environment and the Children themselves. 'Thank you' Darwin responds. Cyclops tells Synch that his ability to copy another mutant's power will act as a redundancy. 'Feels like an insult' Synch mutters, before Cyclops adds that it is also a second set of observational eyes for Darwin and the survival mechanisms of X-23. 'Who, like Wolverine -' Cyclops begins, as Laura interrupts him, announcing that, actually, she is Wolverine. 'You tell 'em, kiddo' Logan smiles.
Cyclops frowns, before continuing: 'Either way... you have the healing ability to withstand the initial temporal shear and live long enough to report back...so we can understand what we're really up against' he explains. Armor drops her force field and exclaims 'You have to tell them the rest. There are risks'. 'Of course' Xavier agrees, and explains that Cerebro cannot penetrate the Vault when it is closed, so they will not know if the three have succeeded or failed – if they live or have died. He explains that they have to get in, get the information and get out, long enough for Cerebro to download them – but if they don't, then the mission will have been for nothing. 'Exactly how long are we going to be gone?' Laura asks. Logan tells her that they believe there are ways to sneak them in, but once they are in, they can't get proof of life or death – they can't resurrect them – until the Vault reopens – and the last time it opened, several thousand years had passed inside.
'You know who they should send on this mission? Wolverine!' Laura snaps, staring at Logan, who replies 'Haven't you been paying attention, kiddo? They are!' He adds that he would go, but that he has got something pressing that can't wait. 'A couple thousand years, huh? You need to pack a pillow, Darwin' Synch grins, rubbing the back of his neck. Hands on hips, Darwin explains that he doesn't need to pack a pillow, as his head can adapt to any contour – 'I meant for me. I'm a two-pillow guy and this very much sounds like an overnight' Synch interrupts, before asking Darwin if he can count on him. 'Yes. You can count on me' Darwin smiles. 'All right then... let's go be heroes!' Synch exclaims.
Inside the Vault, Serafina kneels before a strange mass of wires that appears to wear a mask, while a report for the child pod 5/600 indicates that Serafina was captured, while Sangre, Perro, Aguja and Fuego are all deceased, meaning the mission was a failure. The Vault lists some secondary analysis of the reconnaissance assignment, and notes that mutant resistance is expected, so the Vault opening will be delayed. The Vault then upgrades Serafina and restores Aguja, Perro, Sangre and Fuego, who suddenly materialize alongside Serafina, as the Vault upgrades them all.
Outside the Vault, a storm rages across Ecuador, rain pours and lightning crackles. 'So how are we going to do it?' someone asks. 'Get inside?' one of the mutants asks. 'Yeah' the first remarks. Someone points out that they don't have any idea why Serafina was outside the Vault, but suggests that it has to be an anomaly of some sort, because the Children operate in packs, and no other Children seemed to be active, so right now, they can assume the Children remain in a growth cycle. Someone else adds that they have learned in previous attempts to get in that during those periods, the Children's defenses are automated by the Vault AI. Storm hovers in the air above the head of the Sentinel connected to the Vault – and suddenly unleashes a huge surge of lightning against it. Cyclops announces that the Children are dormant, but actively looking for a breach. 'So first, we're going to get their attention. After that, the automated defense should come online and we'll present as a threat. We'll give them a good show... make them feel it' Cyclops tells the others, as some strange weapons emerge from the Vault and race towards the mutants. 'Here they come!' Cyclops declares as opens fire with an optic blast, taking one of the weapons out. Armor joins in, battling the weapons with her force field, as Storm releases more lightning bolts. 'Make them feel it' Cyclops tells the others, noting that this will all be a distraction.
At that moment, Synch, Darwin and X-23 stand at the entrance to the Vault that Serafina used earlier. They carry with them some Orchis translocators which were salvaged in South America, that Forge repurposed, so they can use those to get inside instead of cracking the door open – after all, the point is to get them inside without attracting attention. The problem with breaking into the Vault is the temporal shear, and most mutants are not built for crossing the threshold, which is why Synch, X-23 and Darwin are being sent. Energy glows around Synch as he reaches out to the opening in the Vault door, while Darwin holds up one of the translocators.
The plan is for Cyclops, Storm and Armor to back off slowly after that, to fake a retreat, withdraw to an area beyond the defense radius. Storm destroys two of the defense weapons with lightning blasts, but doesn't see a third speed up behind her – which strikes her down. 'Got her!' Armor calls out as she catches Storm with her force field. 'Let's get out of here!' Cyclops orders as he fires an optic blast behind him, and then runs alongside Armor, as they let the Vault defenses think they have done their job.
'Mission accomplished' Cyclops remarks once he, Storm and Armor are safely away from the Vault. 'We're clear' Cyclops adds, before asking Storm if she is okay. Storm rubs her head and tells him that she is fine, just a little shook up. 'Did they get in?' she asks. Cyclops tells her that he last saw them at one of the Vault doors – and then a moment later, they weren't.
Inside the Vault – a blue light shines before Darwin, Laura and Synch, as the Vault detects a disturbance. The Vault scans for contagion, and detects that the Vault has been contaminated, although the subjects are unidentified and their class level unknown. The Vault's response to the anomaly is to protect the city, and the technological landscape around the mutants begins to change, 'Oh, $#%&' Synch utters.
Much later: 'How long?' Cyclops asks as he approaches Professor X, sitting in front of some sort of map. 'Three months. Five days. And some change' Charles replies. 'So...how long?' Scott asks again. 'Best guess? Five hundred and thirty-seven years' Charles announces. 'And some change' Scott mutters. 'Yes' Charles agrees. Cyclops frowns as he utters 'My God... what have I done? What the hell was I thinking?'