Arrow is prepared to have a really unexpected return and we will see soon, in an episode of the fourth season.
Haynes has begun filming her guest appearance in the series. He himself has announced via Twitter: "Just landed in Vancouver to start shooting ... #ARROW again !!! So excited !!! "
The executive producer Marc Guggenheim has also confirmed the return of Haynes. "We are more than happy to Colton go back to Arrow this season, "he said in a statement. "It was always our intention to have him back after his departure last season, but it was a matter of finding the right story line to carry it out. That opportunity came in episode 4.12 and can not wait for the fans to see this meeting. "
Despite his departure came the third season, the series was always open for his return. "Colton will not return to the series as a regular character in Season 4 but appear in a further episode of this season" said a representative of Warner Bros. TV in April. "Like all the characters that exist in this universe, there is always the possibility that back on. "