'Well, it can't have been, can it?' The impossibility of the situation was making Jackie snappish again. She swallowed, trying to control her fear. 'You must have just. . taken a wrong turn or something.'

'I've been driving in a straight line,' Joe said.

'It's the fog,' said Jackie. 'You must have driven up a slip road without realising it. Looped round in a circle. It's easily done.'

'Yeah, you're probably right,' said Joe, but he sounded unconvinced.

He drove on, mouth set in a grim line, hands gripping the wheel so tightly that his knuckles stood out in sharp white points. For a few minutes neither of them spoke. Both stared at the road ahead.

Then Jackie's eyes widened. 'Oh God,' she breathed.

The fog was back, same as before, a thick, solid wall of it, directly in front of them.

There was something intimidating about it. Something sinister and challenging. But when he spoke, Joe's voice was carefully upbeat, almost jaunty.

'Well, I suppose this supports your theory that we've come in a circle. We'll just have to be more careful this time.'

Jackie nodded, but said nothing. She felt the muscles in her arms and stomach tightening, instinctively pressed herself back into her seat as the fog enshrouded them again. She'd always hated roller-coasters, always hated that moment when the car clanked its way to the top of the incline and was inching forward in readiness for the downward plunge.

She felt like that now. That awful anticipation. That sense of being out of control and unable to do a thing about it.

Stupid, she told herself. What is there to be scared — Without warning, a figure loomed out of the fog.

She only caught a glimpse of it before Joe was yelling, and yanking on the wheel, and the car was slewing sideways. But in that split second she got the impression of someone tall and ragged and oddly lopsided; someone standing directly in the path of the car, head tilted to one side as if it was too heavy for the spindly neck that was supporting it. She saw no other details. The figure was nothing but a charcoal-grey silhouette on a pearly-grey background.