The Wandering Soul

A dark, country road was no place to be on a chilly October night; that was my motivation for picking the hitchhiker up in the first place.
He seemed the friendly sort, and we chatted for about an hour before he became very quiet.
I'd assumed he'd fallen asleep, but when I glanced in his direction, he was gone.
He'd simply vanished!
Shakily, I stopped the car, and searched the back seat.
Finding nothing, I forced myself to resume driving.
To my horror, there he was, ten miles further up the road, hitching.
I didn't pick him up this time.