The 12th is overrun with homeless vagrants on Christmas; a greeting-card writer snaps; a cattle prod is the weapon of choice for a local merchant.

Friends, foes and felons alike drop by to pay their last respects as the detectives prepare to leave for new assignments; Harris contemplates his resignation when he's assigned to Flushing Meadows; Barney recalls friends departed before he turns out the squad room lights for the last time.