While Oliver questions Slade's loyalty, Team Arrow goes after a new drug dealer named Dragon... and only Diggle knows that Dragon manufactures the steroid that he's using.

Barry and Iris's wedding brings the gang together, but things go awry when villains from Earth-X attack the ceremony. Oliver and the others square off against their counterparts from Earth-X and discover that they're counterparts of Oliver and Kara... and Reverse-Flash, from before his death.