Ronald is a 36-year-old single man from Brooklyn starting an eight-day road trip to Hollywood. He begins his journey with optimism and a desire for a peaceful drive across the country. As his trip progresses, he becomes increasingly anxious and obsessed with a mysterious hitchhiker who keeps appearing along the road. He considers himself a rational person but finds his sense of reality slipping as the days wear on.

The Hitchhiker is a thin, nondescript traveler wearing a cap pulled over his eyes and carrying a cheap overnight bag. He appears drab and weary, consistently showing up along Ronald's route with fresh rain on his shoulders regardless of the actual weather. Though he never acts violently, his inexplicable presence and eerie voice deeply unsettle Ronald.

Mrs. Adams is Ronald's loving and protective mother. She is highly concerned about his cross-country road trip and prophetically warns him about the dangers of the open road, specifically telling him not to pick up strangers. She represents Ronald's strongest connection to home and safety.

A woman looking for a ride who initially appreciates Ronald's offer to drive her. She is bemused by his strange questions about hitchhikers beating cars from town to town. Her practical, grounded nature contrasts sharply with Ronald's erratic behavior when he suddenly veers the car off the road.

A local mechanic who attends to Ronald's car during his drive. He provides practical information about the local weather, noting it has not rained all week, and expresses skepticism about anyone hitchhiking in the area.

The proprietor of a roadside store. He is annoyed at being disturbed during the night and is completely unable to see the menacing presence that Ronald claims is loitering outside his shop.

A woman who is present at Mrs. Adams's home when Ronald attempts to call from a payphone in Gallup, New Mexico. She relays an update to Ronald regarding his mother's current status.

A telephone operator who connects Ronald's long-distance call from Gallup, New Mexico. They coldly track the time limits on the payphone connection, repeating their instructions mechanically.