Martial arts trainer Sienna Lane (Kiana Madeira) thinks she’s finally got her life in order: a nice apartment, her dream job and Jax (Matthew Noszka), the love of her life. Jax and Sienna appear to be an unbreakable duo, growing ever closer as Sienna trains Jax to become the reigning Underground MMA Champion. Everything seems perfect…until she isn’t and Sienna finds out Jax is cheating on her with her younger sister. Faced with the betrayal of those who should be closer to her, Sienna decides to take revenge and intends to hit Jax on her weak points. The perfect opportunity presents itself with Kayden Williams (Ross Butler). Kayden is moody, resentful and undisciplined, but undoubtedly a great fighter. Kayden and Sienna quickly realize that they will have to work together to achieve their goal and defeat Jax in the ring. But when Sienna and Kayden find themselves close but outside the ring, the path becomes more complicated.