The passengers were a homogeneous bunch, all except for one. Twenty white-haired seniors plus a younger man, in a bus that could seat forty. Twelve of the seniors were widowed women.

The other eight made up four old married couples. They were from Seattle. They were a church group on a cultural tour. They had seen the Little Town on the Prairie. Now they were on the long haul west to Mount Rushmore. A side trip to the geographic centre of the United States had been promised. National parks and grasslands would be visited along the way. A fine itinerary, but the wrong season. South Dakota weather in the winter was not famously hospitable. Hence the fifty per cent take up on the tickets, even though the tickets were cheap.

The odd passenger out was a man at least thirty years younger than the youngest of the others. He was sitting alone three rows behind the last of the seniors. They thought of him as a kind of stowaway. He had joined the bus that same day, at a rest stop just east of a town called Cavour. After the Little Town on the Prairie, before the Dakotaland Museum. There had been no explanation. He had just gotten on the bus. Some had seen him in prior conversation with the driver. Some said money had changed hands. No one was sure what to think. If he had paid for his passage, then he was more like a steerage passenger than a stowaway. Like a hitchhiker, but not quite.

But in any case he was considered a nice enough fellow. He was quiet and polite. He was a foot taller than any of the other passengers and evidently very strong. Not handsome like a movie star, but not ugly, either. Like a just-retired athlete, maybe. Perhaps a football player.