Watch your six because “American Assassin” is an unconventional thrill ride with epic fight scenes, big guns, fast cars and shameless characters around every corner.

The screenplay, inspired by the novel by Vince Flynn, ditches the typically formulated action plot and wastes no time diving into what viewers paid to see: action.

The story focuses on Mitch Rapp (played by Dylan O’Brien) who after losing his fiancee to a terrorist attack becomes obsessed with wreaking vengeance on the men who killed her.

This obsession attracts the attention of CIA black operatives who recruit Rapp to join a special task force led by Stan Hurley (played by Michael Keaton).

O’Brien sheds his common portrayal of the geeky, boy-next-door and transforms into a character who is ruthless, rugged and out for revenge.

But as it turns out, there is something sweeter than revenge. It is watching the dynamic between Keaton and O’Brien’s characters as they communicate with sarcasm. Hurley becomes the mentor Rapp was missing by offering field advice.

Both actors bring these somewhat flat characters to life on the screen. Their relationship as a mentor/mentee reaches its climax in the most poignant scene of the film when Rapp disobeys orders to rescue Hurley from the torturous cells of antagonizer “Ghost” (played by Taylor Kitsch).

Hurley’s thanks takes the form of advice, leaving Rapp to smile and move on to catch an escaped “Ghost.”

Rapp, who struggles to play by the op team’s rules or follow orders, reaps no consequence for his reckless behavior in the field, which deterred his growth as a character.

The film, which ran under two hours, is action packed the whole way through but lacks strength in character background and development.

And for all you “Teen Wolf” fans, I can confirm Dylan O’Brien is still as charming as ever.

“American Assassin” is in theaters now.