SPOILER WARNING: This article contains major spoilers for "Vigilante," the latest episode of "Arrow."

Star City is packed full of vigilantes, but not all of them have a heart of gold. That's true of Vigilante, who was introduced in the aptly named episode "Vigilante." In this latest episode of "Arrow," the ski mask-wearing anti-hero had no problem responding with deadly fire when approached by Team Arrow, but he wasn't the only one to show his true colors before the episode was out.

The last scene of the episode found Artemis standing on a rooftop, surveying the streets below. As she kept a lookout, an hulking figure approached her from behind: Prometheus. When she turned to face him, he didn't attack. Instead, she offered him a knowing smile and told him that no one else suspected anything.

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For all appearances, then, Artemis is a mole within Team Arrow. This certainly wouldn't be out of character for the rebellious young vigilante; she butt heads with Green Arrow when they first met in Season 4, and she was horrified to learn he used to kill people when he went by the Hood in Season 1. She certainly has enough motive to turn traitor, but that doesn't mean it's a sealed deal. The scene was brief and didn't have much context, so she could also be acting as a double agent on Team Arrow's behalf. However, that's yet to be seen, and the scene at the end of "Vigilante" does her no favors.

Despite its title, the episode didn't reveal Vigilante's identity. However, it proved he has no intention of making friends with Green Arrow or his new recruits. When confronted, he spat that Green Arrow wasn't doing enough to protect Star City. What's more, he doesn't seem to care about casualties; if anyone stands between him and his goal, he feels no remorse about killing them. Before the credits rolled, Vigilante managed to slip through Green Arrow's fingers with a well-timed smoke bomb, leaving Team Arrow to puzzle over who he could be.

Starring Stephen Amell as the Emerald Archer, "Arrow" airs Wednesdays at 8 pm ET/PT on The CW. The series also stars Emily Bett Rickards, David Ramsey, John Barrowman, Willa Holland and more