Addison returns to Seattle Grace to perform an operation and is surprised by all the changes in the lives of her former co-workers; Derek and Meredith's clinical trial has its first patient; Rebecca returns with shocking news for Alex.

It's New Year's Eve, and Ted hires a limo so they can all party together in style. Things don't go quite according to plan when all the parties they want to get to turn out to be useless.

A couple are murdered on their way to a high school reunion. Jane connects their deaths to a particularly nasty case of childhood bullying but must pull off an audacious plan to flush the killer into the open.

When an Arctic explorer is killed during a polar expedition, the mysterious circumstances of his death take Castle and Beckett from the penthouses of Park Avenue to the halls of the CIA.

The HankMed team attend a divorce party to treat the party planner, and Hank blames Dr Paul Van Dyke for a prescription error that may cost Eric Kassabian his life; Paige makes Evan an offer he can't refuse.

The story of the true father of Vivien's child is revealed, as the man in the rubber suit makes his presence known.

A woman from Cooper's past visits the practice; a pregnant woman experiences severe memory loss after a car accident; Violet and Sheldon argue.

Katie figures out a new way to make the spring gala a success; Greg attempts to be a fun dad and winds up adopting a dog while Katie is occupied with other things.

When a baby abduction is mentioned on the news, Lightman and Foster study the faces of the parents; Lightman thinks that there is foul play from one of them; they dig further into the case to help out with the police investigation of the abduction.

Willis, Mario and Heather perform a radical operation on a maintenance worker stuck under a boiler that has exploded; Angus's father tries to seize power of attorney over Mike, who remains in a coma.

The doctors treat the members of a cult who survived a mass suicide attempt; Mario wants to connect with his late father's girlfriend.

On Halloween night, Willis, Noa and Elliott rush to the scene of a fire at a haunted theatre, where Dr Nolan and her boyfriend's son are trapped.

A citywide blackout during a code black causes chaos. Heather and Elliot are stuck in an elevator with a woman in labour.

Louis promotes Cattleman's Ranch on a local morning talk show, but fears he humiliated himself and his culture.

Jessica schedules mandatory family time with Eddie, Emery and Evan; Louis is set on taking Honey's blog to the next level, landing her a spot on Good Morning Orlando.

Evan is uninvited to a birthday party and Jessica may be to blame. Louis and Eddie perfect their secret family recipe for the chilli cook-off.

For Chinese New Year, the Huangs play a game where they can only speak in Mandarin, which quickly turns into a tense competition between Jessica and Evan.

Jessica suspects an employee at the Cattleman's Ranch is an undocumented immigrant; the restaurant serves as the polling station for the 1996 presidential election; Eddie and his friends debate who killed Tupac.

Louis forgets to thank Jessica in an award acceptance speech for Small Businessman of the Year; Emery, Eddie and Grandma start their own clothing line.

Eli gets a chance to amend a case that he won through questionable tactics; Taylor, Eli's ex-fiancée, joins W.P.K; untimely visions send Eli to Hawaii.