Elysia Rotaru

Oliver and Diggle learn that Merlyn is going to break Darhk out of prison. Meanwhile, Laurel gets a surprising offer.

Following the shocking events in the previous episode, Oliver and Diggle race to rescue Thea, while Felicity, Curtis and Noah join together to stop Darhk.

Clark investigates a recent attack and fears it is the work of a serial killer. Davis fears his blackouts may mean he is the serial killer and confesses his suspicions to Chloe.

In the season four finale, Oliver teams up with a surprising force in an attempt to stop Damien Darhk and his magic once and for all.

When Team Arrow learns what Damien Darhk's devastating next move is, Felicity realizes she needs to ask her father, Noah Kuttler (Tom Amandes), for help. Noah and Oliver have a heart to heart talk that leaves Oliver rattled.

Laurel must deal with the repercussions of taking Sara (guest star Caity Lotz) to Nanda Parbat. Meanwhile, Oliver asks Captain Lance for a favor. And while he's not surprised at the response, he is surprised at what he finds out next.