The "Supergirl" episode "Trinity", directed by Caitlin Parrish & Erica Weiss, airs May 7, 2018 on The CW:
"...still reeling after learning about a secret from 'Lena' (Katie McGrath), 'Supergirl' (Melissa Benoist) asks 'Guardian' (Mehcad Brooks) for a favor that could alter his relationship with Lena forever.
"Meanwhile, with all three 'Worldkillers' united, Supergirl and the team brace for an epic battle..."
Click the images to enlarge...