Chris found Fletcher and closed. The lawyer was rattled - telegraphed clear in the jerky way the car was handling. Chris took a wide swing out into the other lanes so that he’d disappear from Fletcher’s rearview mirror and matched velocities dead level. One hundred and forty on the speedo again - both cars were running dead level and the underpass was only five miles long. Make it quick. Chris closed the gap between the two cars by a yard, flicked on his interior light and, leaning across to the passenger side window, raised one hand in stiff farewell. With the light on, Fletcher couldn’t fail to see it. He held the pose for a long moment, then snapped the hand into a closed fist with the thumb pointing down. At the same time, he slewed the car one-handed across the intervening lane.

The results were gratifying.

Fletcher must have been watching the farewell gesture, not the road ahead and he forgot where he was. He jerked his car aside, pulled too far and broadsided the wall in a shower of sparks. The primer-painted car staggered drunkenly, raked fire off the concrete once more and bounced away in Chris’s wake, tyres shrieking. Chris watched in the mirror as the lawyer braked his vehicle to a sprawling halt, sideways across two lanes. He grinned and slowed to about fifty, waiting to see if Fletcher would pick up the challenge again. The other car showed no sign of restarting. It was still stationary when he hit the upward incline at the far end of the underpass and lost sight of it.

‘Wise man,’ he murmured to himself.

He emerged from the tunnel into an unexpected patch of sunlight. The road vaulted, climbing onto a long raised curve that swept in over the expanses of zoneland and angled towards the cluster of towers at the heart of the city. Sunlight struck down in selective rays. The towers gleamed.