Enemy

A man attends an erotic show at an underground club that culminates with a naked woman on the verge of crushing a live tarantula under her platform high-heel. Elsewhere, a pregnant young woman sits alone on a bed. Adam Bell, a solitary college history professor, rents a movie, Where There's a Will There's a Way, on the recommendation of a colleague. Adam sees an actor briefly; the man at the show. Verifying online, Adam identifies the actor as Daniel St. Claire, the stage name for Anthony Claire. Adam rents the other two films in which Anthony has appeared and develops an interest in the man, who appears to be his physical doppelgänger. Immediately after this, he searches some boxes in his own house and finds a torn out photo. The intact portion of the photo contains someone who looks like himself with some woman's hand over his shoulder. The torn portion of the photo contained the woman, hence her face cannot be identified. Read more on Wikipedia.