‘Yes,’ said Mr Quin. ‘Up till then you suspected them, didn’t you?’ His voice went on, placid and dreamy. ‘Just like something out of a book, you said, colonel. They got the idea there. It’s what the innocent hero and heroine do. Of course it made you think them innocent–there was the force of tradition behind them. Mr Satterthwaite has been saying all along it was like something on the stage. You were both right. It wasn’t real. You’ve been saying so all along without knowing what you were saying. They’d have told a much better story than that if they’d wanted to be believed.’

The two men looked at him helplessly.

‘It would be clever,’ said Mr Satterthwaite slowly. ‘It would be diabolically clever. And I’ve thought of something else. The butler said he went in at seven to shut the windows–so he must have expected them to be open.’

‘That’s the way Delangua came in,’ said Mr Quin. ‘He killed Sir James with one blow, and he and she together did what they had to do–’

He looked at Mr Satterthwaite, encouraging him to reconstruct the scene. He did so, hesitatingly.

‘They smashed the clock and put it on its side. Yes. They altered the watch and smashed it. Then he went out of the window, and she fastened it after him. But there’s one thing I don’t see. Why bother with the watch at all? Why not simply put back the hands of the clock?’

‘The clock was always a little obvious,’ said Mr Quin.

‘Anyone might have seen through a rather transparent device like that.’

‘But surely the watch was too far-fetched. Why, it was pure chance that we ever thought of the watch.’

‘Oh, no,’ said Mr Quin. ‘It was the lady’s suggestion, remember.’

Mr Satterthwaite stared at him, fascinated.

‘And yet, you know,’ said Mr Quin dreamily, ‘the one person who wouldn’t be likely to overlook the watch would be the valet. Valets know better than anyone what their masters carry in their pockets. If he altered the clock, the valet would have altered the watch, too. They don’t understand human nature, those two. They are not like Mr Satterthwaite.’

Mr Satterthwaite shook his head.

‘I was all wrong,’ he murmured humbly. ‘I thought that you had come to save them.’

‘So I did,’ said Mr Quin. ‘Oh! Not those two–the others. Perhaps you didn’t notice the lady’s maid? She wasn’t wearing blue brocade, or acting a dramatic part. But she’s really a very pretty girl, and I think she loves that man Jennings very much. I think that between you you’ll be able to save her man from getting hanged.’

‘We’ve no proof of any kind,’ said Colonel Melrose heavily.

Mr Quin smiled. ‘Mr Satterthwaite has.’

‘I?’ Mr Satterthwaite was astonished.