"Well, mon ami?" he demanded of me breathlessly.

"Forty-six seconds," I replied.

"You see?" He looked round. "There would not have been time for the chambermaid even to take the necklace out, far less hide it."

"Then that settles it on the maid," said the inspector with satisfaction, and returned to his search. He passed into the maid's bedroom next door.

Poirot was frowning thoughtfully. Suddenly he shot a question at Mr Opalsen.

"This necklace - it was, without doubt, insured?"

Mr Opalsen looked a trifle surprised at the question.

"Yes," he said hesitatingly, "that is so."

"But what does that matter?" broke in Mrs Opalsen tearfully. "It's my necklace I want. It was unique. No money could be the same."

"I comprehend, madame," said Poirot soothingly. "I comprehend perfectly. To la femme sentiment is everything - is it not so! But monsieur, who has not the so fine susceptibility, will doubtless find some slight consolation in the fact."

"Of course, of course," said Mr Opalsen rather uncertainly. "Still -" He was interrupted by a shout of triumph from the inspector. He came in dangling something from his fingers.

With a cry, Mrs Opalsen heaved herself up from her chair. She was a changed woman.

"Oh, oh, my necklace!"

She clasped it to her breast with both hands. We crowded around.

"Where was it?" demanded Opalsen.

"Maid's bed. In among the springs of the wire mattress. She must have stolen it and hidden it there before the chambermaid arrived on the scene."

"You permit, madame?" said Poirot gently. He took the necklace from her and examined it closely; then handed it back with a bow.

"I'm afraid, madam, you'll have to hand it over to us for the time being," said the inspector. "We shall want it for the charge. But it shall be returned to you as soon as possible." Mr Opalsen frowned.

"Is that necessary?"

"I'm afraid so, sir. Just a formality."

"Oh, let him take it, Ed!" cried his wife. "I'd feel safer if he did. I shouldn't sleep a wink thinking someone else might try and get hold of it. That wretched girl! And I would never have believed it of her."

"There, there, my dear, don't take on so." I felt a gentle pressure on my arm. It was Poirot.

"Shall we slip away, my friend? I think our services are no longer needed." Once outside, however, he hesitated, and then, much to my surprise, he remarked:

"I should rather like to see the room next door."

The door was not locked, and we entered. The room, which was a large double one, was unoccupied. Dust lay about rather noticeably, and my sensitive friend gave a characteristic grimace as he ran his finger round a rectangular mark on a table near the window.

"The service leaves to be desired," he observed dryly.

He was staring thoughtfully out of the window, and seemed to have fallen into a brown study.

"Well?" I demanded impatiently. "What did we come in here for?" He stared.