"Oh... I'm ten steps ahead of you and you haven't even figured out what game we're playing yet."
Adrian Chase/Prometheus gloating to Oliver about his plan
"Checkmate" is the sixteenth episode of the fifth season of Arrow, and the one-hundred-eighth episode overall. It aired on March 15, 2017.


Oliver gets closer to the truth about Prometheus. Meanwhile, Helix refuses to continue helping Felicity until she does a favor for them.[1]




Preparation ran from January 9, 2016 until January 17, 2017. Shooting ran from January 18 until January 27, 2017.[2]


  • Oliver and the rest of Team Arrow find out that Adrian Chase is Prometheus.
  • When Curtis and Dinah go to find Adrian's mother, Amanda Westfield, in Opal City, they see her house is empty and Curtis refers to Amanda as "a woman who escaped like Norma Bates". This is a reference to the mother of serial killer Norman Bates from the Psycho film series.
  • This is the first appearance of Talia al Ghul in Season 5 in the present day rather than flashbacks.
  • In the flashbacks, Oliver mentions that he doesn't know anyone who could get data off a bullet-ridden laptop, referencing what he asks Felicity to do in the Season 1 episode "Lone Gunmen".
  • Lexa Doig, David Nykl, Adrian Holmes and Mike Dopud previously appeared in the Stargate franchise.