Alleyn pointed out that, whoever the night prowler might have been, he didn’t gain access to the room that night. But Markins instantly objected that this failure must have been followed by success as copies for the designs had been handed over to the Portuguese journalist at Easter. ‘You’re disappointed in my work, sir,’ he whispered dolorously. ‘You’re disgusted and I’m sure I don’t blame you. Put it bluntly, this expert’s been one too many for me. He’s got into that room and he’s got away with the stuff and I don’t know who he is or how he did it. It’s disgraceful. I’d be better in the Middle East.’

‘Well,’ said Alleyn, ‘it’s a poor show, certainly, but I shan’t do any good by rubbing it in and you won’t do any good by calling yourself names. I’ll look at the room. Losse has rigged a homemade but effective shutter that’s padlocked over the window every night. There’s a Yale lock on the door and after the scare he wore the key on a bootlace round his neck. You can gain entrance by boring a hole in the door post and using wire. That might have been the prowler’s errand on the night Grace heard him. He failed then but brought it off some time before Easter. How about that?’

‘No, sir. I kept an eye on that lock. There’d been no interference. While they were away at the races that Easter I took a good look round. The room was sealed all right, Mr Alleyn.’

‘Very well, then, the entrance was effected before the scare, when they were not so careful, and the interloper was returning for another look when Grace heard him. Any objections?’

‘No,’ said Markins slowly. ‘No. He’d got enough to work on for the stuff he handed to the Portuguese, and he kept it until the man got to this country. That’ll work.’

‘All right,’ said Alleyn. ‘Any suspicions?’

‘It might have been the old girl herself,’ said Markins, ‘for anything I know to the contrary. There!’

‘Mrs Rubrick?’

‘Well, she was in and out of the room often enough. Always tapping at the door and saying: “Can my busy bees spare me a moment?” ’

Alleyn stirred and his shadow moved on the wall. It might be difficult to interview Markins at great length during the day and he himself had a formidable programme to face. Four versions of Flossie already and it must now be half-past two at least. Must he listen to a fifth? He reached out his hand for his cigarettes.

‘What did you think of her?’ he asked.

‘Peculiar,’ said Markins.