"There's two types of every legacy, two versions of what we leave behind. There's the good and then the bad. You just really have a lousy habit of focusing only on the bad."
Thea Queen to Oliver Queen
"What We Leave Behind" is the ninth and midseason finale episode of the fifth season of Arrow, and the one-hundred-first episode overall. It aired on December 7, 2016.


After Prometheus attacks Curtis, Oliver realizes Prometheus knows all of Team Arrow's secret identities and is planning to come for them one by one. Felicity and Detective Malone discover a clue that links Prometheus to Oliver's past.[1]


Preparation ran from September 29 until October 10, 2016. Filming ran from October 11 until October 20, 2016.[2]


  • Oliver mentions Die Hard as one of his favorite Christmas movies. That movie also happens to be Stephen Amell's favorite Christmas movie in real-life, which he mentioned that the script was an ad-lib, and also got to fill in the blank.
  • This episode marks the first full appearance of "The Hood" since Broken Dolls.
  • This is the first episode to feature flashbacks that take place during Season 1 instead of the flashback storyline.
  • Oliver and Tommy were mentioned to have been trying to impress Maria Sharapova.
  • The flashbacks in this episode takes place between the end of "Damaged" and "Trust but Verify", because in those episodes Diggle is a member of Team Arrow, but still questions why Oliver so firmly believes in The List, implying that the conversation about how Oliver found his father's message hasn't happened yet. It is confirmed that it takes place before "Betrayal" since Felicity is not a member of the team yet.
  • It's presumed Katie Cassidy was credited in the end credits so her appearance in the episode wouldn't be spoiled.
  • Felicity breaks the fourth wall in this episode; she says "Well, in our town, people who are dead turn out to be secretly alive almost every Wednesday," and new episodes of Arrow air on Wednesday nights.
  • Evelyn betraying Team Arrow is reminiscent of The New 52 which depicted Evelyn joining the Birds of Prey but betraying the team to Mr. Freeze instead.
  • This episode is Arrow's season 5 mid-season finale.
    • This is the last new episode of arrow to air in the year 2016.
  • This is the fifth Christmas-themed episode of Arrow.
  • Prometheus tricks Oliver into accidentally killing Billy, who was dressed up as Prometheus at the time.



  1. Arrow #5.9 Spoiler Description: “What We Leave Behind” - GreenArrowTV
  2. Marc Guggenheim (@mguggenheim) - Twitter