BEGIN SLIDESHOW Arrow episode 6.20 photos: Shifting Allegiances The CW has released the first batch of promo photos for Arrow Episode 6.20, the all-new episode that arrives this Thursday. Check them out in the gallery below! RELATED: Oliver and Diaz Go Toe-to-Toe for Control of Star City in New Arrow Promo Titled “Shifting Allegiances” and set to air April 26, the episode is officially described as follows: “RENE RETURNS TO NTA – Oliver (Stephen Amell) turns to an old friend to help battle Diaz (guest star Kirk Acevedo).