The Flash 2x21 Extended Promo The Flash Season 2 Episode 21 Promo 2x22 S02E21 Preview With Barry gone, the team must figure out a way to handle the return of an old enemy - Girder. Realizing Girder is retracing his steps from his last attack, Iris volunteers to act as bait to trap him in S.T.A.R. Meanwhile, Barry fights to return to his old life. Original airdate 5/10/2016. Subscribe to AresPromo on Youtube for more The Flash season 2 promos in HD. Official website:.