RALPH CONSIDERS CROSSING A LINE TO DEFEAT THE THINKER — When Barry (Grant Gustin) and Team Flash find a way to enter The Thinker’s lair, Ralph (guest star Hartley Sawyer) considers crossing a dangerous line to defeat DeVoe. Meanwhile, Joe (Jesse L. Martin) is concerned by Harry’s (Tom Cavanagh) recent behavior. Hanelle Culpepper directed the episode written by Jonathan Butler & Gabriel Garza (#418). Original airdate 4/17/2018.— (8:00-9:00 p.m. ET)
