The lorry swerved violently but too late for there was a loud report as one of the tyres burst. Again the van slewed across the track, righted itself a few yards from David, and stopped with the engine still running. A man got out on the far side and walked round into the glare of the headlights. He was a very unpleasant-looking man, and it was at once obvious that he was in an ugly mood.

"Glass all over the road," he bellowed. "Spread every where and the tyre is flat. Come and see for yourself."

More growling and swearing followed, and the driver got out as well, and the two of them began to kick the broken glass out of the way. This was David's chance, for he knew that while they were in the glare of the lights looking at the ground the two men would not be likely to see him if he moved.

It could not have taken him more than five seconds to dart, doubled low, across the heather to the back of the van, but it seemed like five minutes. At the edge of the track he stumbled and would have fallen flat on his face but for a strong hand that reached out and helped him up.

"Nice work, David," Jon breathed in his ear. "Where's Tom? He certainly worked the glass trick all right."

"Don't know where he is. He dashed off because he thought he saw someone moving about in the ditch... Shall we chance going in on the back of this, Jon?"

"Listen," Jon whispered.

Jon and David held their breath in suspense as the driver growled to his mate, "Cut down and get the gates open. We can't change the wheel here and I'm not going to try either. Let the others take a turn at some of the dirty work, I'm going to drive in as we are."

The boys felt the van shift as the man climbed again into the driving seat and both boys sighed with relief. Under cover of the engine's roar Jon said, "There's a tailboard thing down here. I think it's safe enough because I came down the hill on it. Hop on, David. You'll have to hang on to that steel bar that locks the double doors. I tried to get into the van but couldn't move that bar... Look out! We're moving!"

David jumped up beside Jon as the van lurched forward.

"I can smell sheep," David whispered as they tried to flatten themselves against the closed doors.

"None in there now, I'm sure," Jon gasped as they were nearly flung off the tailboard. "We should hear them. I reckon the van's empty... We've stopped again. Are we through the gates? Be ready to hop off."