Iris seeks to uncover the mysterious truth about Psych. Meanwhile, Barry initiates a new training system, that could potentially backfire, with devastating consequences. Joe and Cisco make life-altering decisions.

Cisco and Kamila tell the team they are leaving Central City. However, Barry, Iris and Caitlin don't have much time to digest the news because a new version of Rainbow Raider strikes and OG Team Flash must join together one final time to save the city.