For some time he could think of none, but presently an idea occurred to him which he thought might be worth while following up. Some information might be gained through the typewriting of the two forged letters. Could Vanderkemp type, and if so, was his work done with a light or heavy touch? He turned to his companion.

“I wish you would write me a short statement of your movements in London on the night of the crime, stating the times at which you arrived at and left the various places you visited. I should prefer it typed—that is, if you can type. Can you?”

Vanderkemp smiled wanly.

“I think so,” he answered. “I type and write shorthand in four languages. But I’ve no machine here.”

“Borrow one from the office,” French suggested, as he expressed his admiration of the other’s prowess.

It took a personal visit to the office, but Vanderkemp, anxious to defer to the Inspector’s whims, managed to overcome the scruples of the languorous, dark-eyed beauty who reigned therein, and returned triumphant with the machine. Ten minutes later French had his time-table.

Instantly he saw that Vanderkemp typed as an expert—with a light, sure touch that produced a perfect impression, but did not dint the paper. It was a point in the man’s favour. By no means conclusive, it was still by no means negligible.

Inspector French was puzzled. His experience told him that in this world the ordinary, natural and obvious thing happened. A man who secretly visited the scene of a crime at about the hour at which the crime was known to be committed, and who then left the country on a mysterious and improbable mission, the reality of which was denied by its alleged author, a man, further, who had in his pocket bank-notes stolen from the scene of the crime, such a man in ordinary, prosaic, everyday life was the criminal. Such, French thought, was common sense, and common sense, he considered, was right ninety-nine times out of a hundred.

But there was always the hundredth chance. Improbabilities and coincidences did occasionally happen. He would have given a good deal at that moment to know if this case was the exception that proves the rule.

He saw clearly that his second explanation, if somewhat more far-fetched, was still quite possibly true. It certainly might be that Vanderkemp had been duped, that he had been sent on this wild goose chase by the murderer, with the object of drawing on himself just that suspicion which he had attracted, and thus allowing the real scent to cool. A good many of the facts tended in that direction, the forged letters, the keeping of the alleged deal from Schoofs, the fact that no Russian nobleman had turned up at either of the rendezvous named, the travelling under a false name, the warning against communications with the office, and last, but not least, Vanderkemp’s manner during the interview, all these undoubtedly supported the view that the traveller had been used to lay a gigantic false clue.