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.
This crossover begins on Supergirl S5E09, and continues on The Flash S6E09, Arrow S8E08, and Legends of Tomorrow S05E01.
Quest roles:
Brandon Routh(Ray Palmer / The Atom / Clark Kent / Superman), Candice Patton(Iris West), Elizabeth Tulloch(Lois Lane), Tyler Hoechlin(Clark Kent / Superman), Melissa Benoist(Kara Danvers / Supergirl), Caity Lotz(Sara Lance / White Canary), Katherine McNamara(Mia Smoak), Dominic Purcell(Mick Rory / Heat Wave), Jon Cryer(Lex Luthor), Matt Ryan(John Constantine), Tom Welling(Clark Kent (Earth-167)), Erica Durance(Lois Lane), Audrey Marie Anderson(Lyla Michaels / Harbinger), Stephen Amell(Oliver Queen / Green Arrow), Grant Gustin(Barry Allen / The Flash), Johnathon Schaech(Jonah Hex), Kevin Conroy(Bruce Wayne / Batman), Wentworth Miller(Leonard A.I. (voice)), LaMonica Garrett(Mar Novu / The Monitor)