John O'Brien

Cristina treats a former Seattle Grace scrub nurse and is forever changed. Izzie's past comes back to haunt her and makes a case difficult.

Aria has suspicions about Mike's growing friendship with Noel; Ezra gets help from an unexpected source; Toby experiences an unpleasant return to school; Emily and Maya share a final romantic night together.

Bailey interferes in Meredith and Derek's relationship. Alex works hard to gain the trust of a shy patient with a gargantuan tumour.

Everybody seems to know who the father of Rachel's baby is except the man himself. Meanwhile, Phoebe and Joey lie about a gas leak to get into Monica and Chandler's apartment.

Jonah is assigned to work in the gun section and refuses to sell to anyone he deems suspicious. Glenn tries to buy the store's entire stock of morning-after pills.

Meredith fights to keep her emotions in check when a secret about her mother is revealed; Alex and Izzie grow close.