'I understand that about half past two an aircraft came in and took off about half an hour later.'

'That's right, Sir,' the man confirmed their worst fears. 'Quite unexpected it was. Usually we are warned in advance and given the E.T.A. in ample time for whichever of us is on duty to get hold of the others and man the control tower. But with good weather, like it is today, and the strip clear that isn't really necessary. All the same, it's against regulations, and I was a bit took aback.'

'What did you do?'

'I walked over, Sir, and had a word with the pilot. He said that he had come down from our I.C.B.M. Station in the Hebrides to pick up some stuff that was wanted urgent, and he couldn't understand why they had failed to send us a signal about him.'

'What did you do then?'

'I told him he'd better watch out for the aircraft from Farnborough that was due in about half past four, but he said he'd have taken off long before that; so I came back here.'

'Didn't you report this unscheduled landing?'

'I did, Sir, to Flying Officer Leathers, when he and others came along to see the Farnborough arrival in.'

'And what did he say?'

'He entered it in the log, and said he'd send the Hebrides Station a rocket for having failed to warn us that they were sending this aircraft down.'

'Then you let two hours elapse before you reported it?'

The corporal's face became a little sullen. 'Well, it isn't the first time that someone's forgot to send a routine signal, Sir. Anyhow, I didn't think it was anything to get excited about, and neither did my officer when I told him.'

'All right! All right! Describe the pilot to me.'

'He was a tallish chap, age about thirty. Clean shaven, and I think his eyes were brown. He was wearing pilot's kit, not uniform.'

'How many people had he with him?'

'Only one man, Sir. He'd left the aircraft by the time I reached her and, being Sunday, with no one about, he'd walked over to the hangars to get the runabout out for himself. He drove it off towards the laboratory block, to fetch the stuff they'd come for, I suppose.' The corporal turned towards Khune, and added, 'I didn't see him close to, but he was about your build, Sir; dressed like you too, in a mack and a beret.'

'What make was the aircraft,' Verney asked.

'I'm afraid I didn't notice, Sir. She was a two-engined job and I'd say she'd carry up to a ton of cargo.'

'Did you take her number?'

'No, Sir.' The corporal bridled again. 'This isn't like a civil airport, you know, with aircraft coming in from all sorts of places all the time.'

'Hell!' muttered C.B. and, turning, he strode across the passage to the office. He was just about to pick up the telephone when it rang. The corporal, who had followed, murmured, 'Excuse me, Sir,' reached a hand past him, and answered it. After a minute he said: