The CW has released an official description with spoilers for the May 3 episode of Arrow which is called “Docket No. 11-19-41-73.”
(The episode title seems to be a reference to More Fun Comics #73, which featured the first appearance of Green Arrow, likely released on 11-19-41.)
Here’s the write-up. Not a lot of spoilers, but this is what we’ve got. Oh, look! Tommy’s back!
COLIN DONNELL GUEST STARS — The pressure mounts for Oliver (Stephen Amell) who begins to wonder if he will lose everything in his battle to save Star City. A familiar face returns. Andi Armaganian directed the episode with teleplay by Ubah Mohamed & Tyron B. Carter and story by Marc Guggenheim (#621). Original airdate 5/3/2018.