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. Not the best dressed of individuals. He was wearing a creased untucked shirt under a padded canvas jacket. He had no bag, which was strange. But overall it was vaguely reassuring to have such a man on board, especially after he had proved himself civilized and not in any way threatening. Threatening behaviour from a man that size would have been unseemly. Good manners from a man that size were charming. Some of the bolder widowed ladies had thought about striking up a conversation. But the man himself seemed to discourage any such attempt. He slept through most of the drive time and all his responses to conversational gambits had so far been entirely courteous but brief, and completely devoid of substance.

But at least they knew his name. One of the men had introduced himself, on his way back down the aisle from the toilet. The tall stranger had looked up from his seat and paused, just a beat, as if assessing the costs and benefits of a response. Then he had taken the proffered hand and said, ‘Jack Reacher.’

REACHER WOKE UP WHEN THE MOMENTUM OF THE SKID SMASHED his head against the window. He knew where he was, instantly. On a bus. He spent the next split second calculating the odds. Snow, ice, reasonable speed, not much traffic. We’re going to either hit the divider or fall off the shoulder. Worst case, we’re going to tip over. OK for him. Maybe not so good for the old folks in front of him. But probably survivable. He was more worried about the aftermath. Twenty old people, shaken up, maybe injured, cuts, bruises, broken bones, stranded miles from anywhere in a gathering winter storm.

Not good.

Then he spent the next eleven and a half seconds holding on, gently resisting the alternating inertia of the fishtails. He was the rearmost passenger, so he was feeling it worst. The folks nearer the front were swinging through smaller arcs. But they were fragile. He could see their necks snapping from side to side. He could see the driver’s face in the rear-view mirror. The guy was hanging in there. Not bad. But he was going to lose. A luxury bus was a very unwieldy type of vehicle. Be careful what you wish for. He had been in Marshall, Minnesota, for no very memorable reason, and he had hitched a ride with a guy heading west to Huron, South Dakota, but for some private reason the guy wouldn’t take him all the way and had dumped him at a rest stop outside of a place called Cavour. Which had seemed like bad luck, initially, because Cavour was not exactly teeming with transcontinental traffic. But two cups of coffee later a white luxury forty-seat bus had pulled in and only twenty people had gotten out, which meant empty places were there to be had. The driver looked like a straightforward kind of a guy, so Reacher had approached him in a straightforward kind of a fashion. Twenty bucks for a ride to Rapid City? The guy asked for forty and settled for thirty and Reacher had climbed aboard and been very comfortable all day long. But the comfort had come from soft springs and vague steering, neither one of which was doing anyone any favours at the current moment.

But seven seconds in, Reacher was getting optimistic. With no foot on the gas, the bus was slowing. Didn’t feel like it, but it had to be true. Simple physics. Newton ’s Laws of Motion. As long as no other traffic hit them, they would wobble around for a spell and then come to rest, maybe side-on, maybe facing the wrong way, but still right side up and drivable. Then he felt the front tyres bite again and saw they were going to drive straight off the road. Which was bad. But the driver braked hard and held tight through a whole lot of thumping and banging and scraping and they ended up half on and half off the blacktop, which was OK, except they had their asses hanging out in the traffic lane, which was not OK, and there were suddenly no active mechanical sounds at all, like the bus was dead, which was definitely not OK.

Reacher glanced back and saw no oncoming headlights. Not right then. He got up and walked to the front of the bus and saw flat land ahead, all white with snow. No cliffs. No embankment. Therefore no danger from a weight transfer. So he ducked back and started encouraging the geezers to move up the bus towards the front. That way if an eighteen-wheeler slammed into them it might just shear off the rear of the bus without killing anyone. But the geezers were shaken and reluctant to move. They just sat there. So Reacher moved back up front. The driver was inert in his seat, blinking a little and swallowing down his adrenalin rush.

Reacher said to him, ‘Good work, pal.’

The guy nodded. ‘Thanks.’

Reacher said, ‘Can you get us out of this ditch?’

‘I don’t know.’

‘Best guess?’

‘Probably not.’

Reacher said, ‘OK, have you got flares?’

‘What?’

‘Flares. Right now the back of the bus is sticking out in the traffic lane.’

The guy was unresponsive for a moment. Dazed. Then he leaned down and unlatched a locker beside his feet and came out with three warning flares, dull red cardboard tubes with steel spikes on the end. Reacher took them from him and said, ‘Got a first-aid kit?’

The guy nodded again.

Reacher said, ‘Take it and check the passengers for cuts and bruises. Encourage them to move up front as far as they can. Preferably all together in the aisle. If we get hit, it’s going to be in the ass.’

The driver nodded for a third time and then shook himself like a dog and got into gear. He took a first-aid kit from another latched compartment and got up out of his seat.

Reacher said, ‘Open the door first.’

The guy hit a button and the door sucked open. Freezing air blew in, with thick swirls of snow on it. Like a regular blizzard. Reacher said, ‘Close the door after me. Stay warm.’

Then he jumped down into the ditch and fought through the ice and the mud to the shoulder. He stepped up on the blacktop and ran to the rear corner of the vehicle. Blowing snow pelted his face. He lined up on the lane markers and ran thirty paces back the way they had come. A curved trajectory. Thirty paces, thirty yards. Ninety feet. Near enough to eighty-eight. Eighty-eight feet per second was the same thing as sixty miles an hour, and plenty of lunatics would be driving sixty even in a snowstorm. He leaned down and jabbed a flare spike into the blacktop. The crimson flame ignited automatically and burned fiercely. He continued the curve and ran another thirty paces. Used the second flare. Ran another thirty and used the third to complete a warning sequence: three seconds, two, one, move the hell over.