There's a new doc in town. His name is James Peterson (guest star Matt Long). He's taking over the spot in the ER that used to be filled by our deceased friend Pete. James picks one of those rare rainy days in Southern California to begin his first shift. It's a busy one indeed. All of our other favorite docs are called in to serve an overflowing ER because, well, no one in L.A. can drive in the rain.
James treats a young girl, Sarah, who comes in with a fractured wrist. He suspects the injury may be a result of abuse. Cooper disagrees with this theory, as he knows the family well. He convinces James to let him make a call, which he does. Only it's not to the proper authorities. It's to Violet, who learns that the little girl's mom and dad are fighting all the time. It makes her want to run away from home.
Violet advises Sarah's mom and dad to stop fighting in front of her, as it's doing some serious damage. This is moments before the parents return to their child's bed to discover that she's not there. Her raincoat is gone. Sarah's mom hysterically searches the ER area. Charlotte puts the hospital on lockdown. The search is on for Sarah.
Mason worries that what's happening to Sarah's family could happen to him. Cooper assures him that he and Charlotte have already weathered many storms and made it through just fine. In other relationship news, Addison thinks Stephanie is a fantastic nurse even though things get awkward when the subject of Sam pops up. She blabs a bit too much about their past together. Stephanie realizes she's Sam's rebound girl. That's too bad. She really thought he was the one. He's not, which is why she walks away.
Pam is a pregnant woman who is close to her delivery time. Her husband, Todd, is also admitted to the hospital with what everyone believes to be phantom sympathy pains. Only James believes there may be more happening here. He goes around a skeptical Amelia's back to do some tests. The new doc's hunch is aces. Todd has an infection that requires emergency surgery. After Amelia learns James gave her credit for the catch, she fills him in on her difficult past. She also advises him to always take credit for the good things he does.
Jake's patient, Megan has lost her baby during the 12th week. This isn't the first time this has happened. She wants to try again. Addison doesn't think this is a good idea. Too bad Jake didn't ask for her opinion, nor does he want it. He changes his tune somewhat after Megan breaks down in tears after witnessing Pam give birth to a healthy baby girl. Jake and Addison are still mad at each other, but that doesn't mean they can't have angry sex when they get home.
Sheldon isn't a fan of the new ER doc when he tries to shuffle the patient we met in "Mourning Sickness," out the door. James believes Nick, who has urges for young girls, is a sexual deviant who can't be saved. Sheldon feels his patient is making progress, but can't help panicking when he hears that a little girl has gone missing. He realizes his sense of dread was quite noticeable to his troubled patient.
More time passes and Sarah is still missing. A full search of the entire hospital comes up empty. The little girl's raincoat is discovered outside on a bench, but she's nowhere to be found. The case has been turned over to the police. Sarah's parents are devastated upon realizing that their little girl is now a missing person. They don't want to leave the hospital in case Sarah comes back through the front door. Violet is forced to make them face the heartbreaking reality that something like that is not going to happen.