Cyborg [Victor Stone]; Justice League [Green Lantern [Hal Jordan]; Wonder Woman; Flash [Barry Allen]; Batman [Bruce Wayne]; Superman [Clark Kent]; Aquaman [Arthur Curry]] (vision in Victor's nightmares); Darkseid (vision in Victor's nightmare); Wyrmms (malicious code in Victor's systems); Malware (flashback); unnamed S.T.A.R. Labs security guards; Dr. Sarah Charles; Dr. Thomas Oscar Morrow; Dr. Silas Stone; Dr. Silas Stone doppelganger; Elinore Stone (vision in Victor's memory); Britton Claire (vision in Victor's memory); unnamed love of Victor's life (vision in Victor's memory, presumably Dr. Sarah Charles)
Malicious code worms in Victor's systems attack his unconscious mind through his nightmares and memories, while Victor's physical body, with Victor's conscious mind not in control, runs amok in S.T.A.R. Labs. Victor's father continues to be held prisoner by his unnamed doppelganger who has taken his place at S.T.A.R. Labs.