Arrow type TV Show network The CW genre Superhero

The closing moments of Arrow‘s winter finale packed an emotional punch as Oliver was visited by a ghost from his past: Laurel Lance.

After Oliver (Stephen Amell) accidentally killed Felicity’s boyfriend thinking he was slaying big bad Prometheus, the grief-stricken Emerald Archer returned to the Arrowcave and came face-to-face with the late Black Canary (Katie Cassidy), who is now very much alive.

Sure, Laurel’s presence could be the result of Flashpoint, though that’s probably unlikely given the season has been driven by the legacy of the Black Canary. Or a spare bit of liquid from the now-destroyed Lazarus Pit could’ve resurfaced, but Arrow really has moved past bringing people back to life. Laurel could also be a figment of Oliver’s guilt-ridden imagination.

Here’s our theory: This is Earth-2 Laurel Lance, otherwise known as Black Siren.

Viewers first met Laurel’s doppelgänger on The Flash when Zoom (Teddy Sears) brought over his army of meta humans to face-off against Barry Allen (Grant Gustin). But Black Siren, one of Zoom’s top lieutenants, was quickly dispatched by Team Flash and locked up in the pipeline in S.T.A.R. Labs.

With Barry and Team Flash busy tackling Savitar, Prometheus could’ve freed Laurel’s doppelgänger from the pipeline. How could Prometheus pull this off? For one, he seems to know everything about Team Arrow — and not just the information that Artemis has been feeding him. In fact, it’s likely that Prometheus has known who Oliver is all along, which likely means he also knows that Barry Allen is the Scarlet Speedster.

Prometheus made it very clear in the winter finale that he doesn’t want to kill Oliver, but make him suffer a fate worse than death by turning everyone Ollie loves against him. What a better way to do that than by planting another inside man within the team? After all, Prometheus just lost his mole when Artemis (Madison McLaughlin) revealed her true allegiances. Prometheus could’ve filled Black Siren in on Oliver’s history — enough to make the team welcome her back with open arms — and then Prometheus’ path to vengeance would be clear. He even sidelined Diggle (David Ramsey) by getting him arrested, therefore securing that Black Siren could infiltrate the ranks of the team without the voice of reason keeping them from being tricked.

Again, this is all a theory, which means it’s time for you to weigh in with your theories in the comments below.

Arrow returns Wednesday, Jan. 25 at 8 p.m. ET on The CW.