Harry and the Harrisons

"Harry and the Harrisons" is the upcoming twenty-first episode of the fourth season of The Flash, and the ninetieth overall. It will air on May 8, 2018.

Synopsis
With DeVoe’s Enlightenment device nearly complete, in order to disable it The Flash and his team must put their faith in an unlikely ally – Amunet Black. Meanwhile, Harry hits an all-time low when the "Council of Wells" kicks him out but then Cisco introduces him to the "Council of Harrisons".

Trivia

 * The title references the 1987 film Harry and the Hendersons.