Brian, a journalist researching a book on serial killers, embarks on a cross-country journey to California with his girlfriend, Carrie, a photographer. To share expenses, they place an ad for travel companions and find Early Grayce and his childlike girlfriend, Adele. The group sets off in Carrie's car, and as they drive through small towns and visit crime scenes, Brian and Carrie seek material for their book while documenting their experiences. Early initially seems like an ordinary, rough-around-the-edges guy, but his unpredictable nature and odd behavior gradually disturb Brian and Carrie.

As the trip progresses, unsettling events begin to unfold. Early's instability and violent tendencies become increasingly evident. Brian and Carrie start to realize that they may have invited more than they bargained for into their lives. Tensions rise and the dynamic within the group shifts dramatically. The road trip, which began as an adventure for literary research, turns into a precarious situation full of suspense and danger.