The CW has released an official description with new spoilers for the 9th episode of Arrow Season 5.
The episode airs December 7 and is called “What We Leave Behind.”
PROMETHEUS MAKES A DEADLY MOVE AGAINST OLIVER AND THE TEAM — After Prometheus attacks Curtis (Echo Kellum), Oliver (Stephen Amell) realizes Prometheus knows all of Team Arrow’s secret identities and is planning to come for them one by one. Felicity (Emily Bett Rickards) and Detective Malone (guest star Tyler Ritter) discover a clue that links Prometheus to Oliver’s past. Antonio Negret directed the episode written by Wendy Mericle & Beth Schwartz (AR509). Original airdate 12/7/2016.