Watch the special expanded series finale online now.
Last season's cliffhanger finale ended with a blood-soaked Captain Cragen waking up next to Carissa, whose throat had been slit. The night of her murder, Carissa called Cragen because she feared for her life. Cragen met with Carissa in a diner, and at some point during the meal, Carissa slipped a sedative in Cragen's drink. Cragen became groggy, and Carissa helped him home; but Cragen has no idea how she wound up murdered.