Macgregor looked at him cautiously. “Why would ye say that, now?” he ventured to ask. “After all, the whole business, though it was a nasty business, taken all round, was not mysterious. ’Twas a clear enough case. The poor old devil had had a groggy heart for years, and ’twas just unlucky chance that it gave out in that gloomy old mausoleum, and not in some more pleasant place. Anyhow, I dare say that he would have been quite pleased at dying in such circumstances. He seems to have been a regular old bookworm, and to die among his books would please him.”

“Difficult to explain, Macgregor, until I know a little more of the facts,” said Henry.

“Well, what facts do ye want? I’ve got ’em all here—all that were made public, anyhow.”

Henry sighed wearily. “Now, don’t you start that stuff about things being concealed from the public,” he warned his friend. “I get enough and to spare of that from Sarah, who thinks that there is a sort of conspiracy between the Press and the Government to keep all kinds of valuable information secret from her.”

Macgregor grinned. “Ask your questions,” he said. “If you think there’s some fishy business going on here, and can give me the low-down on it, I can promise you that it’ll be published from Land’s End to John O’ Groat’s—and farther.”

“At the moment,” explained Henry, “that’s the very thing that I don’t want. After all, publication often ruins everybody’s chances of catching a murderer.”

Macgregor whistled. “So you think the dear old Professor of English Literature was murdered, do ye?” he asked. “And why would that idea be entering your sweet head, I wonder? After all, ye’re not a suspicious man by nature, and don’t look on all your fellow-men as sunk deep in iniquity, as every born journalist like myself does.”

“Let me explain,” said Henry. “Wilkinson was a Professor of English Literature in an English university.”

Macgregor nodded. “Sceptic though I am,” he said cheerfully, “I’ll grant ye that.”

“Curse that perverted sense of humour of yours,” said Henry with a giggle. “Do please stop fooling in that way, and just listen to what I have to say.”

“I’m all attention, me dear fellow,” said Macgregor.

“He died,” Henry went on, “apparently of heart-failure in the Reading Room of the British Museum some six months ago.”

“Five,” Macgregor interrupted.

“The dates are immaterial,” said Henry. “He died in that way.”

“Yes.”

“Who gave evidence at the inquest?”

Once more Macgregor looked at the pile of papers that lay before him.

“His doctor, his son, and his friend,” he announced at length.

“His friend?” Henry at once seized on what he thought was the important piece of information.