[Warning: The following contains spoilers from Wednesday's Arrow. Read at your own risk!]

After almost an entire season of waiting and guessing, Arrow finally revealed who is underneath Prometheus' mask. The mysterious assassin that's been terrorizing Team Arrow for months is none other than District Attorney Adrian Chase (Josh Segarra).

What a twist! In the comic books, Adrian Chase is actually the alter ego of Vigilante, another masked nemesis of the Green Arrow's (Stephen Amell), who also made his debut this season. In an ironic wrinkle, Prometheus' true identity was revealed during a fight with Vigilante. Prometheus threw Vigilante from a building after trading a few punches, and took off his mask to call it in as D.A. Chase.

It was a shocking moment for the audience, but for the time being members of Team Arrow have yet to find out that one of their closest allies is the one they've been fighting all along. Prometheus, by leaking the Green Arrow's involvement in Detective Mallone's murder, forced Oliver's hand into throwing his alter ego under the bus to the Star City public. Vigilante also miraculously survived the Prometheus attack, so now Oliver must try to protect his city as a wanted cop killer with Vigilante on his tail and Adrian Chase betraying him at every step.

To make matters worse, Adrian has now kidnapped Oliver's girlfriend Susan (Carly Pope), taking their war to the next level. Next week, Oliver will find out that he let this season's big bad into his inner circle and there's nothing he can do about it until he figures out a way to defeat Prometheus.

Prometheus, <em>Arrow</em>Prometheus, Arrow

"It's going to be hard," executive producer Marc Guggenheim told Entertainment Weekly. "It's going to be harder than other big bads we've had because this is sort of the first time we've really played this personal relationship and being betrayed by someone that he had trusted. It's very, very hard for Oliver."

The preview for next Wednesday's episode shows Oliver and Adrian in a game of psychological chess, with Adrian clearly in control of the board. It's going to be a game that Oliver is stuck playing for a while, unfortunately.

"We really wanted to build him up as someone who is extremely good at being 10 steps ahead of Oliver, really being psychological in the way that he manipulates him," executive producer Wendy Mericle said in a conference call to journalists, according to TVLine. "One of the ways he does that is by going after the people that Oliver cares about... He really has no drive to kill Oliver. It's purely based on torture." Taking Susan captive is "part and parcel of this drive to break Oliver down psychologically, as opposed to physically."

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Clearly, Oliver has a major struggle ahead. He's just learned to rely on his team, but Felicty (Emily Bett Rickards) is going rogue and Curtis (Echo Kellum) just found out his husband wants to divorce. Adrian definitely has the upper hand if Team Arrow isn't working in a cohesive manner. Honestly, the person Oliver might want to consult with is his best friend Barry Allen (Grant Gustin) over in Central City. The Flash has a lot of experience with mentors and close friends turning out to be the enemy and betraying his trust.

Arrow continues Wednesdays at 8/7c on the CW.

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