Samuel nodded. “I was expecting someone to come around about that matter, Inspector,” he said.

“You knew he was dead?”

Samuel smiled. “I have my human weaknesses, Inspector,” he said, “and one of them is that I like to read my morning paper at breakfast. I saw the professor’s death reported in it, and guessed that there would be some sort of enquiry about it, since apparently he died suddenly.”

“Not only,” said Shelley, “did he die suddenly, Mr. Samuel—he died mysteriously.”

“Mysteriously?” Samuel looked completely baffled, and then his face cleared up. “You mean suicide?”

Shelley shook his head solemnly. “No, sir,” he said. “I mean—murder!”

“Good God!” Samuel bounced in his chair, sitting bolt upright in amazement, and staring at Shelley as if he were a ghost. “Who on earth would want to murder that poor harmless old fellow?”

“That,” said Shelley somewhat sententiously, “is what I have to find out, if I can, and I am relying on you, Mr. Samuel, to help me.”

“Of course I’ll help you all I can,” replied the solicitor, “though I don’t see precisely what I can do.”

“Well,” Shelley explained, “first of all, have you any papers belonging to the old man here? If so, we might get a line on the motive and so on from them.”

Samuel pressed a button on his desk, and a neat, businesslike typist appeared.

“Get out the box of documents belonging to Professor Arnell, will you, Miss Watkins?” directed the solicitor. “And bring them along here without delay.”

“Yes, Mr. Samuel,” said the girl, and retired once more to some inner sanctum where apparently she worked.

“Dreadful business,” Samuel commented while she was away. “How did it happen?”

Shelley gave him a brief resumé of the circumstances of the crime, but without giving any indication of the general situation, or of the few facts which they had unearthed with regard to the possible identity of the murderer.

Soon, however, Miss Watkins had produced a steel box of documents, had placed it on the desk, together with a fearsome-looking heavy key, and had once more retired to her private office.

“You have the key as well as the box?” asked Shelley in some surprise.

“A duplicate,” the solicitor explained, applying the key to the lock. “The Professor did not like the idea that it might be necessary to get a locksmith to break open the box. He was a very absent-minded old gentleman, and he thought that he might easily lose the key. So he had a duplicate one made, which we kept in the office here.”

“Where was it kept?” asked Shelley, making a note of this state of affairs—for, he told himself, it might afterwards turn out to be important to know who had access to this box of documents.

“In the safe,” replied the other, throwing back the lid of the box, and disclosing a mass of papers.