Arrow 4x18 "Eleven-Fifty-Nine" - Oliver (Stephen Amell) and Diggle (David Ramsey) learn that Merlyn (John Barrowman) is going to try to break Darhk (guest star Neal McDonough) out of prison. Meanwhile, Laurel (Katie Cassidy) gets a surprising offer and Felicity (Emily Brett Rickards) has a heart-to-heart talk with Curtis (guest star Echo Kellum). Rob Hardy directed the episode written by Marc Guggenheim & Keto Shimizu (#418). Original airdate 462016.