Where to watch The Flash Season 4 Online ? First of all, here are some lines about the summary of this season : The mission of Barry Allen, aka The Flash, is once more to protect Central City from metahuman threats. But with Barry trapped in the Speed Force, this mission falls to his family – Detective Joe West; fiancée Iris West; and Wally West/Kid Flash – and the team at S.T.A.R. Labs: Caitlin Snow/Killer Frost, Cisco Ramon/Vibe and brilliant scientist Harrison Wells. When a powerful villain threatens to level the city unless The Flash appears, Cisco risks everything to free Barry. But this is only the first move in a deadly game with Clifford DeVoe, aka The Thinker, a mastermind who’s always ten steps ahead of Barry, no matter how fast Barry runs... Now! Prepare yourself to watch The Flash Season 4 online free. Please help us by sharing The Flash Season 4 with your friends. Thank you for your support! Good viewing.