Although we've already had a big Arrow and The Flash crossover this season, the popular superhero shows have also previously utilised their characters in more minor events. The next team up comes under that latter category, with Arrow's Diggle heading to Central City to help the speedster take down a villain in episode 15 of The Flash.
Speaking with ComicBook.com, executive producer Andrew Kreisberg unveiled more details on what we can expect from the hour: "The Diggles arrive in Central City to help Barry take on King Shark who has escaped from ARGUS and is hellbent on completing his mission of destroying The Flash".
For those not in the know, King Shark is a metahuman sent by Zoom from Earth-2 to kill Barry Allen, and he almost got the job done when he made a surprise appearance in episode 4 of season 2. At the time, producers noted that the character's glorified cameo was "a very expensive 30 seconds", so it's a little surprising to learn that the monstrous villain will be back for a full episode.
It's great news for fans though, and with the always amusing interactions between Diggle and Barry combined with the spectacle that King Shark will no doubt bring, the elements are in place for what should be a fun episode.
Season 2 of The Flash airs Tuesday nights on Sky 1 in the UK and on the CW in the US.