‘Let us take what used to be called a “lunar” at the case. In a little while I must start interviewing people, but I’d like you fellows to get as clear an idea as possible of the case as we know it. At the moment we haven’t got so much as a smell of motive. Very well. Eight students, the model, and Miss Troy have used this studio every morning from Saturday the 10th until last Friday, the 16th. On Friday they used it until twelve-thirty, came away in dribbles, lunched at the house, and then, at different intervals, all went away with the exception of Wolf Garcia, a bloke who models and sculps. He stayed behind, saying that he would be gone when they returned on Sunday. The studio was not locked at any time, unless by Garcia, who slept in it. They reopened this morning with this tragedy. Garcia and his belongings had gone. That’s all. Any prints, Bailey?’

‘There’s a good many blue smears round the edge, sir, but it’s unplaned wood underneath, and we can’t do much with it. It looks a bit as if someone had mopped it up with a painty rag.’

‘There’s a chunk of paint-rag on the floor there. Is it dusty?’

‘Yes, thick with it.’

‘Possibly it was used for mopping up. Have a go at it.’

Alleyn began to prowl round the back of the throne.

‘Hullo! More grist for the mill.’ He pointed to a strip of wood lying in a corner of the studio. ‘Covered with indentations. It’s the ledge off an easel. That’s what was used for hammering. Take it next, Bailey. Let’s find an easel without a ledge. Detecting is so simple when you only know how. Mr Hatchett has no ledge on his easel—therefore Mr Hatchett is a murderer. Q.E.D. This man is clever. Oh, lawks-a-mussy me, I suppose I’d better start off on the statements. How goes it, Bailey?’

‘This paint-rag’s a mucky bit of stuff,’ grumbled Bailey. ‘It’s been used for dusting all right. You can see the smudges on the platform. Same colour. I thought I might get a print off some of the smears of paint on the rag. They’re still tacky in places. Yes, here’s something. I’ll take this rag back and have a go at it, sir.’

‘Right. Now the ledge.’

Bailey used his insufflator on the strip of wood.

‘No,’ he said, after a minute or two. ‘It’s clean.’