Two inseparable sisters, Megan and Abby Graves, are taking one last wild road trip before Megan has to start a new job. The journey includes a trip through remote Arizona in search of a kitchy roadside attraction. Instead, Megan and Abby happen on Skull City Mine, a weather-beaten, abandoned mine town converted into a self-guided tour. What seems like a fun day in the sun turns into a mind-bending fight for survival against menaces both human and supernatural.