Five minutes later Mr Pointz rose with a slight groan from his knees and dusted his trousers sadly. His pristine freshness was somewhat impaired.

‘Eve,’ he said. ‘I take off my hat to you. You’re the finest thing in jewel thieves I’ve ever come across. What you’ve done with that stone beats me. As far as I can see it must be in the room as it isn’t on you. I give you best.’

‘Are the stockings mine?’ demanded Eve.

‘They’re yours, young lady.’

‘Eve, my child, where can you have hidden it?’ demanded Mrs Rustington curiously.

Eve pranced forward.

‘I’ll show you. You’ll all be just mad with yourselves.’

She went across to the side table where the things from the dinner table had been roughly stacked. She picked up her little black evening bag–

‘Right under your eyes. Right…’

Her voice, gay and triumphant, trailed off suddenly.

‘Oh,’ she said. ‘Oh…’

‘What’s the matter, honey?’ said her father.

Eve whispered: ‘It’s gone…it’s gone…’

‘What’s all this?’ asked Pointz, coming forward.

Eve turned to him impetuously.

‘It was like this. This pochette of mine has a big paste stone in the middle of the clasp. It fell out last night and just when you were showing that diamond round I noticed that it was much the same size. And so I thought in the night what a good idea for a robbery it would be to wedge your diamond into the gap with a bit of plasticine. I felt sure nobody would ever spot it. That’s what I did tonight. First I dropped it–then went down after it with the bag in my hand, stuck it into the gap with a bit of plasticine which I had handy, put my bag on the table and went on pretending to look for the diamond. I thought it would be like the Purloined Letter–you know–lying there in full view under all your noses–and just looking like a common bit of rhinestone. And it was a good plan–none of you did notice.’

‘I wonder,’ said Mr Stein.

‘What did you say?’

Mr Pointz took the bag, looked at the empty hole with a fragment of plasticine still adhering to it and said slowly: ‘It may have fallen out. We’d better look again.’

The search was repeated, but this time it was a curiously silent business. An atmosphere of tension pervaded the room.

Finally everyone in turn gave it up. They stood looking at each other.

‘It’s not in this room,’ said Stein.

‘And nobody’s left the room,’ said Sir George significantly.

There was a moment’s pause. Eve burst into tears.

Her father patted her on the shoulder.

‘There, there,’ he said awkwardly.

Sir George turned to Leo Stein.