One day Mr Easterbrook found awaiting his attention a number of copies of an “urgent” and “strictly confidential” memorandum which gave in elaborate detail the plan of a naval operation which for sheer dare-devilry was enough to take one’s breath away. Needless to say, it was “spoof” from beginning to end. But it was spoof so thoroughly plausible in its conception, and so artistically worked out in its wealth of detail, that it might well have deceived someone far better versed than Herr Estbruck in naval matters. I had the privilege of going over it with the distinguished naval officers who drew it up, and I can hear to-day the roars of laughter with which it was received by the company of experts gathered to listen to the elaborate joke. Of course the men who really knew detected the imposture at once; to the novice the plan looked like the details of a gigantic attack on one of Germany’s strongest naval bases.

Now we calculated deliberately that Easterbrook, getting hold of the bogus plan, would be unable to resist the temptation to communicate it to Germany. To him, we knew, it must appear of stupendous importance. It was too elaborate for him to attempt to memorise the details, and far too long to give him a chance of copying it unobserved. Moreover, we decided to convince him, if possible, that he could purloin a copy without risk.

Now with confidential documents of importance, every single copy must be accounted for. The printing is done under the closest supervision; the exact number of sheets of paper required is issued; every official who receives a copy signs for it and gets a receipt when he parts with it. Mr Easterbrook had been well drilled in the routine. We had made him especially careful by inducing him on one occasion carelessly to sign for four copies of a document when he only received three, and the trouble we raised about the “missing” copy must have made him determined to count his copies in future. We relied on that to catch him and his associates.

Early one morning a messenger laid upon Mr Easterbrook’s desk four copies of the naval plans.

“Please sign for three copies of Number 27162 A.B., Mr Easterbrook,” said the lad, laying the book before him.

A keen-eyed watcher saw Mr Easterbrook glance at the heading of the document which lay before him. Clever though he was, he was unable to repress a start of astonishment as the amazing title, carefully designed for the occasion, caught his eye. A moment later he had recovered himself, counted his copies of the paper, and, glancing at the book, signed for three. The bait was swallowed!

I must now hark back to Madame Gabrielle to make clear the chain of events which followed. The sprightly Frenchwoman soon found out that beneath an unprepossessing exterior her employer concealed an extremely amorous disposition. Exerting the full power of her fascinating personality, she soon began to exercise a considerable influence over the financier, and was able at length to solve the problem of the mysterious perfume.

A few hours after the secret “plans” had been laid before him, Easterbrook made a clandestine arrangement to dine with Madame Gabrielle at a restaurant in Soho the next evening.

“I have to go out of town to-night,” he said. “I don’t want to write, but if you get by to-morrow’s post a plain sheet of paper scented with geranium I shall be there. If it is scented with violet you will know I have been detained and cannot come.”

So the secret was out at last! The wedding card had been a signal to Cauvin that all was well. Had it been scented with violet it would have indicated danger. As will be seen, we had little difficulty in guessing the purpose of Easterbrook’s absence from his house that night!