Meredith has that motherly instinct. She knows when Zola is awake even if there's no evidence to support her feeling. Casey (guest star Sarah Chalke of How to Live with Your Parents (for the Rest of Your Life)) is another mom who has a feeling about her son, Parker. Jo diagnoses him with a virus, but Casey knows in her gut something else is wrong. She has a bunch of yellow notes from all the research she's done online. All tests say her son has strep throat. Only Meredith is willing to dig a little deeper. It's a mom thing.
A CAT scan on Casey's son shows that everything is normal. Meredith still is willing to listen to this worried mom's thoughts. She owns the hospital. If she wants to do more tests then she's going to do more tests. All signs again point to strep until Jo learns that the test was a false positive. Meredith realizes there is something seriously wrong with Parker. It happens to be Kawasaki's Disease, which is one of the possibilities Casey wrote on her yellow slips. This determined mom fought and fought. She never gave up. Meredith lets her know that because of her efforts she just saved her son's life.
A gas tanker slams into an SUV. Lots of casualties come pouring into the OR. They are covered in gasoline, so no open flames allowed. This goes especially for the patient who wants to grab smoke. Owen takes a young boy, Ethan, under his wing as the team works hard to save his mom and dad. Both are in pretty bad shape. BOOM! The tanker from the accident blows. More casualties are on the way. This includes the human fireball flailing around outside. It seems the patient actually did step away to grab his smoke.
Heather joins Derek and Shane as they work on Ethan's mom. She impresses with her quick hands. Derek continues to test her reflexes after the surgery. Shane isn't too pleased that his boss appears to have a new favorite intern. As for Ethan, he's upset when his mom wakes up but doesn't remember him. As for the boy's dad, Cristina repairs his aorta. When he starts to crash, she pulls a risky move that is questioned by Owen. But at the end of the day, they know they both want what is best for the patient.
April treats a pregnant woman whose baby is in distress. Alex helps push the umbilical cord back inside her. The baby needs to come out now. April is going to assist until she sees Matthew is one of the injured ER visitors. Jackson offers to check him out. As for April, she struggles to save the mom with Jason (aka Chest Pecwell). The worried dad arrives to hold his new baby, but he's in anguish because his wife is still fighting for her life. April witnesses his heartfelt plea for her to come back to him.
April believes the universe kept pulling her patient to with her husband. They were meant to be together. Unfortunately, it won't be forever. The patient crashes and can't be revived. April is hit hard by the loss. Jackson comforts her to the point where it looks like they might kiss. Alex wants Chest Pecwell break the news to the dad. This doesn't happen. C.P. says she wasn't his patient, so Alex does his job. These two guys really don't like each other. As for April, she's not sure what to do when Matthew says he loves her.
Everyone wants a genome map from Bailey's new lab. In other news, Callie has been selected to give a big speech on cartilage at a big conference. She's pretty nervous about it. She's also going to miss it because of all the patients rolling in. This may not be a bad thing, as Arizona leads her to believe her speech was a bit dry. Nevertheless, Richard sets up a camera so the speech can be given via video stream. Callie is nervous at first, but loosens up once she ditches her note cards. That's because she's speaking from the heart.
At the end of a long day, Jackson doesn't seem as happy as Stephanie is when they meet up at the bar. Alex is his typically ornery self as he orders a beer. Shane lets Heather know that he's not going to let her snake neurosurgery out from under him. As for Meredith, she wants Bailey to map Zola. She also wants her own map. She wants to know if she's going to get Alzheimer's. Meredith wants to know that she'll be able to fight for her kids like the other mom she met today did.