'Arrow' Season 4 Spoilers: Colton Haynes' Roy Harper/Arsenal Has Returned To Star City?

The twelfth episode of Arrow Season 4 boasts of an all-star cast, as Katrina Law returns as Nyssa al Ghul and Tom Amandes will play the mysterious villain the Calculator. In addition to that, Colton Haynes will reprise his role as the Green Arrow's sidekick Arsenal. But why exactly has Roy Harper returned to Star City?

New images from the episode Unchained have just been released and there are a few photos that confirm Haynes' return to Arrow as Arsenal. One photo shows the vigilante standing alongside John Diggle (David Ramsey) and Black Canary (Katie Cassidy) while another image seems to show Oliver Queen (Stephen Amell) confronting Roy.

TWO MORE DAYS to a new #Arrow, Arrowheads - featuring the return of @ColtonLHaynes as Roy! https://t.co/h1yMWNM4yb pic.twitter.com/RjTRgfzQg1

— Arrow - GreenArrowTV (@GreenArrowTV) February 1, 2016

But the biggest question remains: Why has Roy decided to rejoin Team Arrow? Fans believe that he might try to get back together with Thea Queen (Willa Holland), who is now a member of Oliver's team. It's no secret that the two had an on-and-off relationship but things could get really complicated since Speedy has a new boyfriend now. If Roy has returned to try and win Thea back, he would probably need to try harder to do so.

However, there are also speculations that there is a darker reason why Roy has suddenly shown up in Star City. There is a possibility that a bigger threat is on its way to the city and Arsenal has returned to warn Team Arrow.

Roy was initially introduced as a recurring character in the first season of Arrow before becoming a series regular in the second and third season. Haynes had decided not to return to renew his contract at the conclusion of Season 3.

Find out why Roy is back when Unchained, the twelfth episode of Arrow Season 4, airs on the CW on February 3.