S4, E6: Felicity is frantic when she learns that Ray Palmer (guest star Brandon Routh) is alive and being held by Damien Darhk. Felicity's guilt over not finding Ray sooner causes tension between her and Oliver. Meanwhile, Sara joins Laurel, Thea and the team on a rescue mission for Ray. However, the effects of the Lazarus Pit take over and threaten to jeopardize the entire operation. And Felicity's mother, Donna (recurring guest star Charlotte Ross) returns to Star City.