‘I wasn’t satisfied to let it go like that,’ said Douglas. ‘I was damned worried, and next day I kept the tag on Master Markins. Once or twice I caught him watching me with a very funny look in his eye. That was on the Thursday. Flossie had given him the Saturday off and he went down to the Pass with the mail car. He’s friendly with the pubkeeper there. I thought things over and decided to do a little investigation and I think you’ll agree I was justified, sir. I went to his room. It was locked, but I’d seen a bunch of old keys hanging up in the store-room and after filing one of them I got it to function all right.’ Douglas paused, half-smiling. His arm still rested along the back of the sofa behind Terence Lynne. She turned and, clicking her knitting-needles, looked thoughtfully at him.

‘I don’t know how you could, Douglas,’ said Ursula. ‘Honestly!’

‘My dear child, I had every reason to believe I was up against a very nasty bit of work; a spy, an enemy. Don’t you understand?’

‘Of course I understand, but I just don’t believe Markins is a spy. I rather like him.’

Douglas raised his eyebrows and addressed himself pointedly to Alleyn.

‘At first I thought I’d drawn a blank. Every blinking box and case in his room, and there were five all told, was locked. I looked in the cupboard and there, on the floor, I did discover something.’

Douglas cleared his throat, took a wallet from his breast pocket and an envelope from the wallet. This he handed to Alleyn. ‘Take a look at it, sir. It’s not the original. I handed that over to the police. But it’s an exact replica.’

‘Yes,’ said Alleyn, raising an eyebrow at it. ‘A fragment of the covering used on a film package for a Leica or similar camera.’