Sneak Peek footage, images and synopsis from the "Arrow" episode "What We Leave Behind", written by Wendy Mericle, Beth Schwartz and directed by Antonio Negret, airing December 7, 2016 on The CW:
"...'Prometheus' makes a deadly move against 'Oliver' and the Team, attacking 'Curtis' (Echo Kellum). Oliver realizes Prometheus knows all of Team Arrow’s secret identities and is planning to come for them one by one.
"Then 'Felicity' (Emily Bett Rickards) and 'Detective Malone' (Tyler Ritter) discover a clue that links Prometheus to Oliver's past..."
Click the images to enlarge and Sneak Peek "Arrow: What We Leave Behind"...