In addition to classic DC Comics villain the Calculator making his debut on this week's episode of "Arrow," Arsenal makes his return to Star City as well. The question is, does it have anything to do with Thea Queen, or is there some darker reason for Roy Harper's return?

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ROY HARPER RETURNS; NYSSA MAKES HER MOVE -- The team faces off against a formidable villain nicknamed The Calculator (guest star Tom Amandes). Meanwhile, Nyssa (guest star Katrina Law) makes her move and Roy Harper (guest star Colton Haynes) returns to Star City. Kevin Fair directed the episode written by Speed Weed & Beth Schwartz (#412). Original airdate 2/3/2016.

"Arrow" airs Wednesday nights at 8 p.m. on The CW.