Nan Adams, 27, on a cross-country road trip from New York City to Los Angeles, gets a flat tire on U.S. Route 11 in Pennsylvania and survives losing control of the car and skidding onto the shoulder. The mechanic she has called to come put a spare tire on comments that he is surprised she survived, saying "you shouldn't have called for a mechanic, somebody should've called for a hearse". He directs her to follow him into town where he will supply her with a new tire. As she is driving from the site of her blow-out, Nan notices a shabby and strange-looking man hitchhiking. Later, as she is preparing to leave the service station in town, she again sees this hitchhiker; but the mechanic does not see him when she mentions it. Unnerved, she drives away. As she continues her trip, Nan sees the same hitchhiker thumbing for a ride again in Virginia and at several other points in her journey.