With a sense of bewilderment Dikon sat down and waited. These two amazing old gentlemen appeared to have effected a swap of their respective personalities. As far as his native mildness would permit, the Colonel had now assumed an air of austerity; Dr Ackrington’s manner, on the contrary, was almost propitiatory. He glanced sharply at Dikon, looked away again, cleared his throat, and began.

‘Falls,’ he said loudly, ‘had no intention of infringing the bounds that he himself had set upon the extent of his investigation. You will remember that the area between the two points where the red-flagged path deviated from the white-flagged one was to be regarded as out of bounds. He had arrived at the first red flag on this side of Taupo-tapu and was about to turn back when he was arrested by a suspicious noise.’

Dr Ackrington paused for so long that Dikon felt obliged to prompt him.

‘What sort of noise, sir?’ he asked.

‘Somebody moving about,’ said Dr Ackrington, ‘on the other side of the mound. Under the circumstances Falls decided—rightly, in my opinion—that he’d go forward and establish the identity of this person. As quietly as possible and very slowly, he crept up the mound and looked over it.’

With a sudden dart that made Dikon jump, Colonel Claire thrust a box of cigarettes at him, muttering the preposterous phrase: ‘No need for formality.’ Dikon refused a cigarette and asked what Mr Falls had discovered.

‘Nothing!’ said the Colonel opening his eyes very wide. ‘Nothing at all. Damned annoyin’. What!’

‘The fellow had either heard Falls coming,’ said Dr Ackrington, ‘or else he’d finished whatever game he was up to and bolted while Falls was climbing the mound; in my opinion the more likely explanation. He’d a good start and although Falls went some way down the other side and flashed his torch, there wasn’t a sign of anybody. Fellow had got clean away.’

Dikon felt foolish and therefore rather annoyed.

‘I see, sir,’ he said. ‘Obviously, I’ve been barking up the wrong tree. But Simon and I had some further cause for believing Mr Falls to be a rather mysterious person.’

He paused, wishing he had held his tongue.

‘Well,’ said Dr Ackrington sharply, ‘what was it, what was it?’

‘I thought perhaps Simon had told you.’

‘Simon hasn’t honoured me with his theories which, I have no doubt, constitute a plethora of wildcat speculations.’