The Monitor sends Harbinger to gather the worlds’ greatest heroes - Supergirl, The Flash, Green Arrow, Batwoman, White Canary, The Atom and Superman in preparation for the impending Crisis. With their worlds in imminent danger, the superheroes suit up for battle while J’onn and Alex recruit Lena to help them find a way to save the people of Earth-38.
Elenco: Melissa Benoist , Chyler Leigh , David Harewood , Mehcad Brooks , Jeremy Jordan , Katie McGrath , Chris Wood , Jesse Rath , Nicole Maines , Odette Annable , Floriana Lima , Calista Flockhart , Andrea Brooks , Azie Tesfai , Julie Gonzalo , Staz Nair .