Pariah enlists Black Lightning to help stop the Anti-Monitor after Flash-90 Shares what he learned from his battle in Elseworlds. With Black Lightning’s help, Barry Cisco and Killer Frost come up with a plan that could save them. Iris has a heart-to-heart with Ryan Choi. Oliver and Diggle return to an old familiar stomping ground.

The group uses Ray’s invention to track new recruits to help save the universe. The Monitor sends Iris, Clark and Lois in search of a mysterious Kryptonian, while Kate and Kara head out to find Bruce Wayne. In addition, Mia challenges Sara, Rory discovers a hidden talent, and Lex Luthor returns.

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. J’onn and Alex recruit Lena to help them find a way to save the people of Earth-38.

Supergirl’s struggle against Leviathan reaches a boiling point as she faces off against Rama Khan. As Lena and Hope work to launch Project Non Nocere, Hope proves to be an invaluable asset to Lena.

Supergirl finally learns the truth about Lena while tangling with Leviathan. J’onn J’onnz makes a discovery about his brother’s whereabouts.

While a new villain is under arrest at the DEO, Supergirl uses him to try and understand who is responsible for the recent attacks. Meanwhile, Andrea and Lena think back on their tumultuous past.

On the eve of the worldwide launch of Andrea Rojas’s VR contact lenses, Kara and William team up on an investigation that exposes a terrorist plot. Kelly and Alex celebrate an anniversary, but Alex’s safety is in jeopardy.

Kate and Alice continue their sister/nemesis dance, while Alice and Mouse construct their most evil plan yet. Mary invites Kate to a special event honoring Catherine and Jacob makes a decision that leaves Kate perplexed.

With The Flash freshly infected by the monstrous Bloodwork, Iris and Cisco battle to help Barry take control of himself before he’s lost forever to Ramsey’s influence. The rest of Team Flash fight to reclaim control of Central City from Bloodwork’s growing army.

Oliver’s mission takes him to Lian Yu where he tries to ignore the repercussions of the looming Crisis until he receives help from an old friend. A united Team Arrow faces a recognizable villain.