Oliver Queen (Stephen Amell) has been having a rough time as beating his current nemesis, Prometheus (Josh Segarra), seems to be the most difficult challenge he has faced so far. In "Arrow" season 5 episode 18, the frustrated hero will use his connection with the powerful Russian mafia, Bratva, to take down Prometheus once and for all.

In the previous episode, Prometheus (also known as Adrian Chase) was able to break Oliver down and make him admit that he killed the people on his father's list not only to fulfill a promise but also because he liked the act of killing itself. After Oliver's confession of this dark secret, the villain freed the heroic vigilante from captivity, and the episode ended with Oliver returning to his team and telling them that he was done being the Green Arrow.

However, the fight is not over yet, as Oliver is seen talking to his Bratva brother, Anatoly Knyazev (David Nykl), in the trailer for episode 18 titled "Disbanded." In the video, he is heard telling the gangster, "I need you to kill Adrian Chase." According to the episode synopsis posted on Comic Book, John Diggle (David Ramsey) and Felicity Smoak (Emily Bett Rickards) will be shocked by Oliver's decision to ask help from the dangerous Russian mafia, resulting in John confronting him regarding the matter. 

Prometheus, being a different kind of villain, will not be terrorizing Star City during the finale. The city will be safe, and according to a statement given by Executive Producer Marc Guggenheim to Entertainment Weekly, the finale will not even be taking place in Star City. He also indicated, "You can expect a good number of returning characters, characters you haven't seen in a while, back in the episode."

In other news, the "Arrow" tech genius, Felicity, is reportedly crossing over to DC's "Legends of Tomorrow" as a superhero. She is finally suiting up after years of being a sidekick, but there is a big chance that it is going to be a different version of her — a Felicity from an alternate reality. This could be a result of the Legion of Doom rewriting reality as they see fit, using the Spear of Destiny.