What We Leave Behind

"What We Leave Behind" is the upcoming ninth episode of the fifth season of Arrow, and the one-hundred-and-first episode overall. It will air on December 7, 2016.

Synopsis
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.

Production
Preparation ran from September 29 until October 10, 2016. Filming ran from October 11 until October 20, 2016.