Lost Souls

"Lost Souls" is the upcoming sixth episode of the fourth season of Arrow and the seventy-fifth episode overall.

Synopsis
Felicity is frantic when she learns that Ray 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. Donna Smoak returns to Star City.

Production
Preparation ran from August 28 until September 8, 2015. Shooting began September 9, 2015 and ran until September 21, 2015.