Even though he despises bankers, Holmes agrees to consult on a case involving the death of a Wall Street executive who appears to have overdosed on heroin. Meanwhile, with Holmes’ encouragement, Watson tries to re-enter the dating scene.

Aware that Derek might never operate again, Meredith stops talking about the surgeries she's performing. Meanwhile, Richard calls on Dr. Catherine Avery to help him perform a complicated procedure, as things continue to heat up between Jackson and April; and Arizona's struggle to accept her fate forces Callie and Alex to face their guilt.

The gang make a disturbing discovery after crashing Maureen's wedding.

Real estate mogul Donald Trump; from "The Voice," musician Adam Levine; musical guest Carly Rae Jepsen

A job offer for Ben causes Leslie to contemplate their future. Ron and Andy take Diane's girls out trick-or-treating. Tom searches for a new business idea.

Reese and Finch wonder if they should intervene when they learn that a mob enforcer's life is in danger; Finch turns to an unexpected source for help.

A DC college student goes missing and her grieving parents come to Pope & Associates for help. Meanwhile David is still investigating the Cytron case and gets help from a very surprising source; and in the White House, Fitz feels the pressure as Mellie proves once again that she's a political powerhouse.

The gang heads to Stuart's comic book store to celebrate Halloween; Leonard uses science to seduce Penny.

Ovulation cycles sway female voting, Tom Hanks concocts neutral Halloween costumes, and Indiana Governor Mitch Daniels talks about his book, "Keeping the Republic".

From "Vegas", actor Michael Chiklis; from "The Twilight Saga: Breaking Dawn – Part 2", actress Maggie Grace; comedian and actor Eddie Izzard dropy by for the cold open to promote "Mockingbird Lane" and helps with reading the tweets and e-mails.

A kid's birthday party interferes with Pete's planned paintball outing. Meanwhile, Ruxin has a run-in with a sushi chef.

It's Halloween in the office and Andy invites his college a cappella group to perform, which leads to a confrontation with his frenemy Broccoli Rob. Meanwhile, Dwight finds evidence that a madman is loose in the office and tries to track him down, and the first meeting of Jim's new job causes a fight with Pam.

Connor continues his search to uncover the secrets of Mystic Falls and tries to convince Jeremy to work with him. With Dr. Fell’s help, Damon and Klaus question Connor, but the confrontation takes a lethal turn. Trying to keep her new life as normal as possible, Elena is determined to continue her senior year at Mystic Falls High with support from Matt and Caroline. Rebekah’s arrival at school makes it difficult for Elena to control her anger, but she learns that confronting Rebekah can be extremely dangerous. Later, Rebekah realizes how alone she is, and reaches out to April. Stefan takes Elena on a thrilling motorcycle ride in an effort to show her that life can still be fun. Tyler gets a surprise visit from Hayley, a werewolf who helped him through the ordeal of breaking his sire-bond to Klaus. Concerned about Elena, as well as his own emotions, Stefan turns to a sympathetic Caroline for advice.