So, the lights are out, the backup lights are really dim, and Seattle continues to be a place where bad and dangerous situations only ever get worse and actually deadly. The backup power holds for a little while but then goes out completely, so Frank the maintenance guy goes down to try and figure out what is going on. Meanwhile, Fetus is in a totally horrible position and so they have to do a c-section. Once the baby is out he doesn't cry for a moment as we all saw fifty times in the commercials, but then he turns out okay. His numbers are a little bit low, though, so Derek takes him up to the NICU. With Cristina having been pulled into an urgent heart surgery, Smash and Heather are left with Mere and when the OB is pulled to another delivery, Smash takes over the last bit of sewing up Mere's c-section incision. She starts to bleed heavily, though, and she realizes she must have been hurt in the fall and not realized it because she then went into labor and any pain she had just melted together with the contractions. She walks Smash through the surgery as far as she can so that he can try and find the bleed, and Heather runs for help.

Bailey thought she was ready for surgery again but when she gets into the OR and is faced with actually having to cut, she finds she still can't do it. Richard takes over but as they work he realizes there's a problem with the guy's heart. As if that wasn't enough, the power fully goes out so they have to work with just headlamps and flashlights. He calls Cristina to come help but she's adamant that she can't operate in the dark. Richard points out that the guy is going to die if she doesn't operate, and eventually he's able to talk her into doing the procedure and then talks her past one moment of panic so that she can sense where the problem is and repair it even with almost no light. Afterward, she thanks him sincerely for making her a better surgeon. He's still riddled with guilt for yelling at Bailey since it obviously didn't help, but Ben points out that he hasn't been able to help either, and Bailey knows that he cares about her. Richard then decides to go down to the basement to see what is taking Frank so long with the generators.

Since she won't operate, Bailey tries to find other ways to help such as delivering blood to the ORs and getting pain meds for the patients who are pouring in. But with the power out, the pain med locker can't be opened since it requires and electronic code. She and Leah try to get it open but nothing works, and finally Heather runs up to find help for Smash as he tries to save Meredith. Bailey snaps and beats up the medicine locker with an IV stand, which breaks it open and frees the pills. She then tells Leah to take the meds to the ER, and she goes with Heather to help Mere. She requests an extra set of gloves and hesitates a moment, but finally jumps in and gets back to work. Cristina finds out what's going on and she and Derek wait in the hall for any word; when Bailey comes out she's so overcome with emotion that she starts bawling and they fear the worst. But Mere is totally okay, and when she starts to apologize for scaring them, Derek grabs her in a giant bear hug. Once Mere wakes up, she and Derek decide that Fetus' real name should be Bailey.

Earlier in the evening, Cristina had gone up to the roof with Owen as he sent Ethan and Paul in a helicopter to Seattle Pres. When she sees how he is with the kid and how hard this is for him, she starts to ask him about his wanting a family. Owen insists that he just bonded with this one particular kid, and that all he wants is her. But at the end of the day, after watching Derek and Meredith and their kids together, she goes to talk to him again. She asks him if she would really be enough for him, for the rest of his life, and while he desperately wants to say yes, she knows that the answer is no and leaves, adding sadly that their breakup really already happened.

In a scene that was supposed to be dramatic but was so over the top as to make me burst out laughing, a bus driving down the street skids, hits some cars, flies into the air, lands on its side, and bursts into flame, all in front of the ER. The docs all run out to help get everyone out before the whole thing explodes, and they seem to do it just in time. But as Jackson is about to walk away he sees a shoe and finds the little girl cowering under the wreckage, not wanting to come out. He pleads with her but nothing, and then the bus explodes. April and Matthew had both been helping and were outside when it happened and April had been yelling at Jackson to clear the area not realizing he was down there with a child. When the bus explodes she totally loses it, but then Jackson comes triumphantly walking through the flames with the girl in his arms. Later, when Callie is treating him, April freaks out and descends on him, shoving and hitting him, and Callie has to scream at her and force her away. Poor Matthew looks a tad worried when he sees a shirtless Jackson and I think April's reaction might have clued him in to the fact that Jackson was the one to whom she gave her precious flower. She then goes to see Jackson later and admits that she wants him, and if he can give her a reason not to then she won't marry Matthew.

After Lauren and Arizona's sexual escapade ends, Arizona gets dressed and practically sprints away, consumed by guilt. She then gets upstairs to the NICU where Alex and Princess are holding down the fort with all the tiny humans and their very worried parents. When the backup generator goes out all is fine for a few moments since the ventilators are on batteries but then the batteries all start to die and no one had thought to stock more. Lauren shows up to try and help and while Arizona tries to send her away, Alex has her stay since they need her. Arizona admits to Alex that she cheated and feels horrible, but Alex counters that every girl he's been with had been normal before they got together with him and became crazy and damaged. That's actually debatable, but his point is that Arizona is a way better person than he is. When the batteries all start to die everyone panics that there aren't enough doctors to manually ventilate the babies but Derek, there with Fetus/soon-to-be-Little-Bailey points out that there are enough adults, and Princess walks them through how to do it, making everyone feel reassured and confident that they can get through this. Alex is so touched that he tells her he loves her, and despite the fact that she is afraid because their friendship is so perfect, he convinces her this is right and the two start making out. And I just threw up in my mouth a little bit.

When Callie gets upstairs to check on Arizona she notices Arizona's wedding ring pinned to Lauren's shirt -- looks like there was a bit of a post-coital wardrobe mix-up. She and Arizona get into a giant fight where finally Arizona screams at Callie that she wasn't on the plane and despite the fact that she acts like one of them, she has no real idea what they went through and never will. She then, to Callie's horror, brings up the leg YET AGAIN. Callie and I thought that was finally over, and Callie points out that she did it to save Arizona's life, but it does rather look like the end of the road for these two.

When the lights finally come back on, Bailey tells Ben she feels horrible about what she said to Richard and she wants to find him immediately and apologize. Earlier when Richard went downstairs to look for Frank, he found him slumped over having just had a heart attack. Richard sloshes through the water that is slowly filling the basement and took care of him, and when Frank was being taken upstairs he told Richard that he found the problem, and someone just needs to flip the switch. This obviously happened, since the lights turned back on, but as Bailey goes to look for Richard the last shot we see of him shows him lying in a pool of water, cables sparking all around him, and his lab coat totally burned and smoking. It's not a Grey's finale without someone beloved possibly dying, right?