Meredith reaches out to Teddy and helps her talk through some of her personal struggles; Owen and Amelia hide out near Betty's school after she becomes a flight risk; Jo wants to get to work on the fellowship, but Bailey's attention is elsewhere.

After Annalise chooses Gabriel as her second chair, the unexpected duo puts all of their efforts into Nate Sr.’s murder re-trial as they try to convince a jury to grant an insanity plea. Bonnie struggles to rebound after a dark part of her past resurfaces.

A young woman wakes up in the hospital with no memory of her assault, and Carisi’s investigation stalls when she disappears.

Still trying to solve the mystery of what happened to Dean, Sam enlists the help of Sheriff Jody Mills who may unknowingly already be on the case. Castiel continues to be a father figure to Jack, who surprises even himself, when a life is on the line.

When an employee costume competition is announced, Amy and Mateo aren’t afraid to play dirty to win first prize – a paid day off. Glenn is preoccupied by Cloud 9’s new automatic cart collector. Garrett is tormented by an annoying Halloween novelty song.

When Wolowitz dresses up as Sheldon for Halloween, Sheldon seeks retaliation at Leonard and Penny’s Halloween party. Also, Leonard is shocked that Penny doesn’t remember their first kiss.

The group explores the three main branches of ethical thought.

Comic Tiffany Haddish; journalist Steve Kornacki; Buddy performs.