The CW has released the official synopsis for "Haunted," the forthcoming fifth episode of Arrow's fourth season.

In the episode, Matt Ryan comes to see Oliver as John Constantine, offering his help in helping to bring Sara back to her own personality.

You can check out the synopsis below.

“Haunted” — (8:00-9:00 p.m. ET) (TV-14, LV) (HDTV)

MATT RYAN REPRISES HIS ROLE AS JOHN CONSTANTINE ON ARROW — When things take a turn for the worse with Sara (guest star Caity Lotz), Oliver (Stephen Amell) calls in a favor from an old friend who deals in the mystical, John Constantine (guest star Matt Ryan). John Badhamdirected the episode written by Brian Ford Sullivan & Oscar Balderrama (#404). Original airdate 11/4/2015.