"A seemingly impossible robbery at Queen Consolidated’s Applied Sciences Division brings Central City police scientist Barry Allen (guest star Grant Gustin) to town. Citing a similar case back home, Barry offers to help Oliver (Stephen Amell) and team with the investigation. Oliver senses there is more to Barry than meets the eye, but he’s distracted by the similarities between this current case and something that happened on the island. Meanwhile, Felicity (Emily Bett Rickards) takes a liking to Barry, which doesn’t go unnoticed by Oliver. Sin (guest star Bex Taylor-Klaus) asks Roy (Colton Haynes) for help when a friend of hers goes missing. Roy is surprised when Thea (Willa Holland) not only encourages him to help, but joins the search. Unfortunately, Sin’s friend is connected to Brother Blood (guest star Kevin Alejandro), and their search ultimately gets one of them seriously injured."
Meanwhile, The CW is adding another familiar DC Comics villain to its ever-expanding Rogues Gallery, with Graham Shiels (Thor: The Dark World) set to play Cyrus Gold, a.k.a. Solomon Grundy, in episode nine. Of course, given Arrow's'realistic' take, it's unlikely we'll see him as a zombie... for the time being at least. Here's the official episode description for 'Three Ghosts'...
"After a fight with Cyrus Gold AKA the Acolyte (guest star Graham Shiels), Oliver (Stephen Amell) is drugged and left for dead. Determined to cure him, Felicity (Emily Bett Rickards) makes a risky decision. The cure causes Oliver to hallucinate, and what he sees forces him to confront his past. Meanwhile, Barry (guest star Grant Gustin) continues to help Felicity, and their connection grows stronger. The Arrow asks Lance (Paul Blackthorne) to look into Gold, but when the stakeout on Gold goes bad, someone is killed. Roy (Colton Haynes) is captured and tortured by Brother Blood (guest star Kevin Alejandro)."
Arrow airs on The CW on Wednesday evenings.