Arizona screams for the truck driver to call 911 after the car crash. Callie has gone through the windshield and is lying on the hood of the car, severely injured.
At the hospital, Meredith pulls Mark out of surgery to tell him what has happened. He rushes out where Richard and the others are waiting for the ambulance. Richard insists that Mark sit this one out - Callie and the baby are his family. The ambulance arrives and Arizona jumps out spouting medical jargon. Mark looks horrified as he sees Callie covered in blood. As they wheel her inside, Owen pleads with her to stay with them. Arizona and Mark call out to Lucy to tell them if there is a fetal heartbeat. Rickard asks them to stand back as the team works furiously to stabilize Callie. Just as they find the fetal heartbeat, Callie starts to crash. They bring her back and wheel her into the elevator for surgery. Arizona is left standing alone, and gasps, "I asked her to marry me and a truck came out of nowhere."
In surgery, Owen orders everyone to take a deep breath. Arizona watches from the window, and Richard sends Lexie in search of Mark. Bailey hollers that there are bleeders everywhere as Derek works on Callie's brain. Owen announces they have to close her up or she'll bleed to death. Bailey explains that she'll go to ICU now. Lucy tells Richard she's out of her depth where the baby is concerned.
As Lexie finds Mark and comforts him as he cries, Karev soothes Arizona who also breaks down. Mark tells Lexie, "She's my best friend."
Karev goes with Lucy to the roof to greet Addison Montgomery, who is being brought in to look after the baby. She dismisses Lucy after learning she didn't stop the contractions. Addison whispers to Callie that they'll come up with a plan.
In the x-ray room, Owen tries to organize the group when they all argue about Callie's treatment. Karev tells Meredith and Christina that the only treatment that might save Callie could kill the baby. Meredith notices a hickey on his neck and they tease him about Lucy. Down the hall, Arizona and Mark get into a huge argument about whether the priority should be to save Callie or the baby as April and Bailey tend to Callie. Mark tells Arizona she's nothing. Jackson catches up with Lexie and tells her Callie will go back to the OR tomorrow, but they have to decide whether to deliver the baby. Lexie lets him know she needs to stay near Mark. Jackson gets it. In the on call room, Derek worries to Meredith about how to tell Mark that Callie may not come back.
In her mind, Callie goes back in time to the car ride. She tells Arizona what is going to happen an Arizona orders her to put on her seatbelt. Callie says she loves her. She imagines the other couples - Bailey and Eli, Owen and Christina, Henry and Teddy, Lucy and Alex, and Derek and Meredith all getting passionate as they sing.
Derek and Meredith wake Callie in her bed and ask her to follow their fingers. They go out and tell Mark and Arizona it's just too soon to tell. In the x-ray room, Christina makes her case to Owen and Teddy about a technique for heart surgery that Burke used to use. Teddy nixes it. Owen sides with Teddy, causing Christina to leave upset.
Arizona sits with Callie and pleads with her to live. Callie moves her fingers. As Addison suggests Mark go in and make peace, Callie crashes again. They rush her to surgery. In the observation window, Arizona tells Mark they should pray. He says he hasn't stopped since they brought her in. During surgery, Owen changes his mind about the heart surgery. Teddy is told to step away and Christina takes over. They wind up with one minute to re-start Callie's heart before Addison takes the baby. The baby is delivered and Arizona steps in to care for it. Callie's heart begins to beat again.
After surgery, Derek tells the others they have to wait to see if Callie wakes up. If her brain's been compromised she won't wake up. Mark apologizes to Arizona. In the elevator, Meredith whispers to Derek that she was jealous of Callie because she got pregnant without trying. She sobs and questions the universe. Derek holds her and promises they'll be parents.
Arizona goes in and tells Callie about the baby - she is one pound and is looking for her. Meanwhile, Lexie tells Jackson she's ready to go home with him, and Teddy tells Christina she can't teach her anymore. In her room, Callie awakens and tells Arizona she'll marry her.
Wow! What an intense, emotional episode - exactly as I was hoping and expecting it would be. As for the singing element, it seemed very organic and fitting at times, particularly when Callie was singing, but at other times it felt out-of-place and even slightly cheesy. It certainly didn't take away from the episode for me on the whole, however. Excellent trauma drama tonight! What did you think of the music event? Be sure to tell me in the comment section below.