Connor brings Robin back to Med, and Sarah & Dr Charles start to suspect that her problems may not be psychiatric after all. The first round of tests, but they find a tumor when they run an MRI. When Robin wakes up after surgery, Charles visits her and they start repairing their relationship.
Connor is introduced to his new co-fellow, and they don't hit it off. He's patronizingly smug, and she has not interpersonal skills.
Will obsesses about what Nat's new haircut means, and ends up dumping Nina, leaving him homeless. He asks Nat to dance at Noah's graduation party.
Sarah's ex "returns" a gift she gave him which really seems like a weird attempt to let her know he's moved on. Noah keeps hitting on her.
Choi declines Noah's invitation because of his failed pass at April; Noah tells April that she should move on Ethan because he's a doc makes good money; the two end up kissing on a boat at the party.
Stohl gets pranked by interns (and probably Maggie).
After the asshole patient, Kellogg, is left waiting all day, he confronts Dr. Charles outside of the hospital, shooting the doctor and then himself.