Primer is a science fiction film directed by Shane Carruth, following two engineers, Aaron and Abe, who inadvertently discover a method of time travel while working on a side project. As they explore the complexities and ethical ramifications of their invention, they grapple with the unpredictable consequences that arise. Carruth also stars as one of the protagonists, delivering a narrative that intricately explores the paradoxes and existential dilemmas of time manipulation.