“The young fellow whose name and address were found on Marbury,” replied Rathbury.  “I remember.”

“Breton is engaged to Aylmore’s daughter,” continued Spargo.  “Breton took me to Aylmore’s club.  And Aylmore gives a plain, straightforward account of the matter which he’s granted me leave to print.  It clears up a lot of things.  Aylmore knew Marbury over twenty years ago.  He lost sight of him.  They met accidentally in the lobby of the House on the evening preceding the murder.  Marbury told him that he wanted his advice about those rare things, Australian diamonds.  He went back with him to his hotel and spent a while with him; then they walked out together as far as Waterloo Bridge, where Aylmore left him and went home.  Further, the scrap of grey paper is accounted for.  Marbury wanted the address of a smart solicitor; Aylmore didn’t know of one but told Marbury that if he called on young Breton, he’d know, and would put him in the way to find one.  Marbury wrote Breton’s address down.  That’s Aylmore’s story.  But it’s got an important addition.  Aylmore says that when he left Marbury, Marbury had on him a quantity of those diamonds in a wash-leather bag, a lot of gold, and a breast-pocket full of letters and papers.  Now—­there was nothing on him when he was found dead in Middle Temple Lane.”

Spargo stopped and lighted a fresh cigarette.

“That’s all I know,” he said.  “What do you make of it?”

Rathbury leaned back in his chair in his apparently favourite attitude and stared hard at the dusty ceiling above him.

“Don’t know,” he said.  “It brings things up to a point, certainly.  Aylmore and Marbury parted at Waterloo Bridge—­very late.  Waterloo Bridge is pretty well next door to the Temple.  But—­how did Marbury get into the Temple, unobserved?  We’ve made every enquiry, and we can’t trace him in any way as regards that movement.  There’s a clue for his going there in the scrap of paper bearing Breton’s address, but even a Colonial would know that no business was done in the Temple at midnight, eh?”

“Well,” said Spargo, “I’ve thought of one or two things.  He may have been one of those men who like to wander around at night.  He may have seen—­he would see—­plenty of lights in the Temple at that hour; he may have slipped in unobserved—­it’s possible, it’s quite possible.  I once had a moonlight saunter in the Temple myself after midnight, and had no difficulty about walking in and out, either.  But—­if Marbury was murdered for the sake of what he had on him—­how did he meet with his murderer or murderers in there?  Criminals don’t hang about Middle Temple Lane.”

The detective shook his head.  He picked up his pencil and began making more hieroglyphics.

“What’s your theory, Mr. Spargo?” he asked suddenly.  “I suppose you’ve got one.”

“Have you?” asked Spargo, bluntly.