EW has learned that Susanna Thompson will also be returning to Arrow as Moira Queen, mother to Oliver (Stephen Amell) and Thea (Willa Holland).
Arrow, The Flash, Legends of Tomorrow and Supergirl will all come together this fall, with the crossover event scheduled to fall on Arrow‘s 100th episode (the 8th in the upcoming fifth season).
Should Robert or Moira return for more than a single episode, that would be a game-changer for the team dynamic.
We’ve already learned that both Deathstroke and Robert Queen (Jamey Sheridan) will be returning for this episode, along with Katie Cassidy’s Black Canary.