Neil Sandilands

With Barry in the speed force, Iris, Kid Flash, Joe, and Vibe must protect Central City; a powerful armored villain threatens to level the city if the Flash doesn't appear; Cisco decides to break Barry out of the speed force.

When Native American artifact collectors are attacked by a meta who can bring inanimate objects to life, Barry turns to a surprising ally for help; Harry enlists Cisco's help to determine the identity of The Thinker.

Barry comes face to face with DeVoe; DeVoe's past is revealed; Iris puts the final touches on the wedding, only one week away.

Amunet threatens to kill Caitlin if she doesn't help perform a tricky medical task; The Thinker traps The Flash in a speedster-proof prison; Iris is forced to choose whether to save Caitlin or Barry.

In the Season Four finale, Team Flash gets help from a surprising ally in their battle against DeVoe.