‘No. He may have been afraid of leaving some trace of himself. If that’s the case he’ll want to destroy or lose them. It was low tide at three o’clock this morning. To drop them in the river he’d have to get to a bridge. What sort of house is Dimitri’s?’

‘It’s a small two-roomed flat in the Cromwell Road. He keeps a servant. French, I should say.’

‘We’ll go round there at noon when he’s due at the Yard, and see if we can find anything. You’ve seen the flat. Where’s his telephone?’

‘On the landing.’

‘Right. You’d better ring from the nearest call-box as soon as I’ve gone in. Keep the servant on the telephone as long as possible. You can put a string of questions about the time Dimitri got in, ask for the names of some of the men, anything. I’ll have a quick look round for a possible spot to hide a largish parcel. We must get the dust-bins watched, though he’s not likely to risk that. Blast this nephew. Fox, go and do your stuff with the maids. Don’t disturb Lady Mildred, but ask for Mr Donald’s telephone number. It’s written on a memorandum in her room, but they may have it, too.’

Fox went out and returned in a few minutes.

‘Sloane 8405.’

Alleyn reached for the telephone and dialled a number. ‘Chief Detective-Inspector Alleyn, Scotland Yard. I want you to trace Sloane 8405 at once, please. I’ll hang on.’

He waited, staring absently at Fox, who was reading his own notes with an air of complacent detachment.

‘What?’ said Alleyn suddenly. ‘Yes. Will you repeat that. Thank you very much. Good-bye.’

He put back the receiver.

‘Mr Donald Potter’s telephone number,’ he said, ‘is that of Captain Maurice Withers, one hundred and ten Grandison Mansions, Sling Street, Chelsea. Captain Maurice Withers, as you will have noticed, appears in Lord Robert’s notes. He was at the cocktail-party at Mrs HalcutHackett’s and “seemed thick with her.” He was at the concert when Dimitri took her bag. Now look at this—’

Alleyn took a cheque book from a drawer in the desk and handed it to Fox.

‘Look at the heel of the book. Turn up June 8th, last Saturday.’

Fox thumbed over the leaves of the heel until he found it.

‘Fifty pounds. M. Withers. (D) Shackleton House, Leatherhead.’

‘That’s the day of the cocktail-party at Mrs Halcut-Hackett’s. This case is beginning to make a pattern.’

Fox, who had returned to Lord Robert’s notes, asked:

‘What’s this he says about Captain Withers being mixed up in a drug affair in 1924?’