Like a pendulum, way back there. The rear of the bus set about trying to overtake the front of the bus. It didn’t get far. Just a few crucial degrees. The driver did everything right. He fought the skid. But the steering was feather light and the front tyres had lost traction. There was no feedback. The back of the bus came back in line and then swung out the other way.

The driver fought hard for three hundred yards. Twelve long seconds. They felt like twelve long hours. He spun the big plastic wheel left, spun it right, tried to catch the skid, tried to stop it building. But it built anyway. It gathered momentum. The big pendulum weight at the back slammed one way, slammed the other. The soft springs crushed and bounced. The tall body tilted and yawed. The back of the bus swung forty-five degrees left, then forty-five right. Bridge Freezes Before Road. The bus passed over the last of the concrete tubes and the front tyres bit again. But they bit while they were turned diagonally towards the shoulder. The whole bus turned in that direction, as if following a legitimate command. As if it was suddenly obedient again. The driver braked hard. Fresh snow dammed in front of the tyres. The bus held its new line. It slowed.

But not enough.

The front tyres crossed the rumble strip, crossed the shoulder, and thumped down off the blacktop into a shallow ditch full of snow and frozen mud. The underbody crashed and banged and scraped on the pavement edge for ten long feet before all momentum was spent. The bus came to rest at an angle, tilted a little, the front third in the ditch, the rear two-thirds still on the shoulder, and the engine compartment hanging out in the traffic lane. The front wheels hung down to the limit of their travel. The engine had stalled out and there was no sound beyond hot components hissing against the snow, and the air brake gently exhaling, and the passengers screaming, then gasping, then going very quiet.