Erin was raised in a survivalist compound by her father, which taught her a variety of skills. She went on a trip with her boyfriend/former literature teacher to attend his parents anniversary party. While attending, a group of killers wearing animal masks attacks the guests. Erin takes charge by securing the home, finding weapons for the remaining survivors, and setting up traps to kill the intruders. As she single-handedly takes out the Tiger, Lamb, and Fox killers, she comes to learn that two of the surviving family members Felix and Zee hired the killers. After a brutal fight, Erin kills both of them, then learns her boyfriend who had left to get help was also part of the contract killings. When he returns to the house, she kills him.