Poirot murmured:

‘C’est bête, c¸a!’

‘Oh, come now, Poirot, old man, you mustn’t judge everybody else by the light of your shining intellect! As a matter of fact that’s the sort of little detail that’s quite apt to be overlooked. Door’s locked. People break in. Woman found dead—pistol in her hand—clear case of suicide—she locked herself in to do it. They don’t go hunting about for keys. As a matter of fact, Miss Plenderleith’s sending for the police was lucky. She might have got one or two of the chauffeurs to come and burst in the door—and then the key question would have been overlooked altogether.’

‘Yes, I suppose that is true,’ said Hercule Poirot. ‘It would have been many people’s natural reaction. The police, they are the last resource, are they not?’

He was still staring down at the body.

‘Anything strike you?’ Japp asked.

The question was careless but his eyes were keen and attentive.

Hercule Poirot shook his head slowly.

‘I was looking at her wrist-watch.’

He bent over and just touched it with a finger-tip. It was a dainty jewelled affair on a black moiré strap on the wrist of the hand that held the pistol.

‘Rather a swell piece that,’ observed Japp. ‘Must have cost money!’ He cocked his head inquiringly at Poirot. ‘Something in that maybe?’

‘It is possible—yes.’

Poirot strayed across to the writing-bureau. It was the kind that has a front flap that lets down. This was daintily set out to match the general colour scheme.

There was a somewhat massive silver inkstand in the centre, in front of it a handsome green lacquer blotter. To the left of the blotter was an emerald glass pen-tray containing a silver penholder—a stick of green sealing-wax, a pencil and two stamps. On the right of the blotter was a movable calendar giving the day of the week, date and month. There was also a little glass jar of shot and standing in it a flamboyant green quill pen. Poirot seemed interested in the pen. He took it out and looked at it but the quill was innocent of ink. It was clearly a decoration—nothing more. The silver penholder with the ink-stained nib was the one in use. His eyes strayed to the calendar.

‘Tuesday, November fifth,’ said Japp. ‘Yesterday. That’s all correct.’

He turned to Brett.

‘How long has she been dead?’

‘She was killed at eleven thirty-three yesterday evening,’ said Brett promptly.

Then he grinned as he saw Japp’s surprised face.

‘Sorry, old boy,’ he said. ‘Had to do the super doctor of fiction! As a matter of fact eleven is about as near as I can put it—with a margin of about an hour either way.’

‘Oh, I thought the wrist-watch might have stopped—or something.’

‘It’s stopped all right, but it’s stopped at a quarter past four.’

‘And I suppose she couldn’t have been killed possibly at a quarter past four.’

‘You can put that right out of your mind.’

Poirot had turned back the cover of the blotter.