The gang comes together for the Barry and Iris wedding, but the ceremony is crashed by villains from Earth-X..

Barry comes face to face with DeVoe, whose past is revealed through flashbacks.

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

Caitlin fears that her past time as Killer Frost may be back to haunt her, Felicity helps celebrate the bachelorette party while Barry is taken out for a night on the town.

Gypsys father, Breacher, takes an immediate disliking to Cisco and decides to hunt him and Barry runs into his old nemesis, Ralph Dibny.

A new meta called Hazard causes bad luck for Barry and the team; Harry Wells returns to Earth-1.

Barry deals with the ramifications of abandoning Iris while facing a meta who can control technology.

Barry is brought out of the Speed Force to help fight an armored villain, but he isn't the same person.

With nothing left to lose, Barry takes on Savitar in an epic conclusion.

Barry chooses to use any means necessary to save the woman he loves; The Flash turns to Captain Cold for help.