DC’s Legends of Tomorrow 3×17 “Guest Starring John Noble” Season 3 Episode 17 Promo – SEEING DOUBLE — With the timeline barely stable, the Legends must tackle two anachronisms at the same time to try and keep Mallus at bay. Sara (Caity Lotz) and Rip (guest star Arthur Darvill) team up to stop Grodd (guest star David Sobolov) from going after a particular target leaving Nate (Nick Zano) and Wally (Keiynan Lonsdale) to stop Amaya (Maisie Richardson-Sellers) from changing her future. Meanwhile, the Legends think they have found a way to destroy Mallus, but they will have to create an uneasy alliance with one of their enemies. Brandon Routh, Dominic Purcell and Tala Ashe also star. Ralph Hemecker directed the episode written by Keto Shimizu & James Eagan (#317). Original airdate 4/2/2018.