The protagonist David is a former Green Beret and when he comes home he finds out there is a serial killer on the loose that has been killing random people at a local state park. David starts learning jiu jitsu and trains at an MMA gym near his house while he takes online classes to become a conservation officer and works part time at a gun store. David meets a cop named Evan while training at the gym who he becomes good friends with and the two hunt together several times before the climatic battle at the end. David spends his spare time searching for the killer and when he finally finds the antagonist responsible for all the murders a gunfight ensues. David manages to get the upper hand on the killer after Evan is mortally wounded.