Khune shrugged. 'That can't be helped. There are limits to what one can convey on the astral, and it had to be some place that he could easily identify. I had nothing of this kind in mind at the time, but I meant to tell him that up there some bird-watcher might chance to see us through a pair of binoculars; so, before I handed him the paper, it would be best for us to walk down to the wood on the far side of the slope. It was there that I meant to kill him.'

'I'd like you still to carry out that idea as, about fifty yards inside the wood, we could arrange an ambush and he would have much less chance of slipping through our fingers.'

When Khune had agreed, they continued to talk about Lothar for a further quarter of an hour; then it was settled that they should all meet at half past nine next morning and go out to reconnoitre Lone Tree Hill. Forsby accompanied the others out into the avenue and, when they had said good night to Khune outside his bungalow, walked on with the visitors to theirs. As they halted in the doorway, C.B. said:

'Well, Dick, we've had a lucky break. I'm very much happier about this job than when I arrived here this afternoon.'

'So am I.' Forsby nodded. 'In the worst case now, if Lothar does get away, it will be only with a useless bit of paper. All I hope is that he doesn't get wind of what is in the air and fail to turn up.'

'I regard that as much less likely than I did an hour ago. He can't be as sensitive as I feared to what goes on in Otto's mind, otherwise he would have tumbled to it on Thursday night, when Otto agreed to go to London, that he didn't mean to bring the formula with him, and instead had cooked up an idea for doing him dirt.'

'That's true, Sir,' Barney commented. 'All the same, wouldn't it be best to leave Otto behind when we make our reconnaissance tomorrow? If Lothar took it into his head to have a look at him, and saw him with us selecting hideouts from which to trap him, it's a certainty that he'd call his visit off.'

'Good for you, young feller.' Verney turned to the Squadron-Leader. 'Sullivan's right, Dick. We can't be too careful. Slip along to Otto now. Tell him to try to put tomorrow's business out of his mind before he goes to sleep, and that you are going to reinstall the old tape recorder just in case Lothar comes through to him during the night. And that tomorrow we would like him to remain in his bungalow till lunch time.'