The "Arrow" started his crusade alone, but afterwards, Oliver Queen was joined by John Diggle, Felicity Smoak, Roy Harper, and Laurel Lance. This season four, Thea Queen will become a full-pledged member of the team.

On "Arrow's" official Facebook account, CW released a high definition snap of Thea wearing a red archer costume.

The Red Archer was Roy Harper, but he was called the Arsenal, and many can remember that in order to save Oliver Queen from being executed, Roy had to step up and took his vigilante identity. Diggle and Felicity then had to fake Roy's death to make the world believe that the "Arrow" is gone.

Thea's costume resembles Roy's, when he was still the Arsenal, and it was only adjusted to fit her size. Despite her efforts to be known as the Red Arrow, Comic Book Resources learned that her team mates continue to call her Speedy, her childhood nickname.

We've seen trailers with Thea showed off her skills as a melee fighter and an archer. According to Cinemablend, she learned that in Corto Maltese, from her father Malcom Merlyn, now the new Ra's Al Ghul.

Meanwhile, after becoming a member of the League of the Assassins and defeating the head of the demon in season three, Oliver Queen decided to leave the life of a vigilante behind. He jetted off to some faraway place with Felicity to start a new life, as per SuperHeroHype.

The sudden appearance of Damien Darhk, however, created complications. Oliver Queen will, once again, set foot on the now-Star City as the Green Arrow to defend it.

Thea, while helping the team defend the city, will find herself still struggling from the effects of coming out from the Lazarus Pit. That said, is it possible that Thea's experience will affect her allegiance?

As she struggles with its effect, will she remain a friend to Team Arrow or will she eventually become their foe?

We'll find out more. "Arrow" season four premieres tonight, 8 p.m. EST, on CW.