He had suddenly remembered a statement made by Cheyne when he was giving his first rather incoherent account of his adventures. The young man said that it had been arranged between himself and Joan Merrill that if either were lucky enough to get the tracing into his or her possession, the first thing he or she would do would be to photograph it. Now, in juxtaposition with that statement, French recalled the facts, first, that Joan must have reached her flat on the night of her abduction at least several minutes before Blessington and Sime arrived with their car; and secondly, that during those minutes she had the tracing with her—the genuine tracing, as there was every reason to believe. Had Joan photographed it?

French was overwhelmed with amazement and chagrin at his failure to think of this point before, nor could he acquit Cheyne of a like astounding stupidity. For himself he felt there was no excuse whatever. He had even specially noticed the girl’s camera and the flashlight apparatus which she used for her architectural details when he was searching her rooms, but he had then, and since then up till this moment, entirely and completely forgotten the arrangement made between the partners.

Late as it was, French decided to go then and there to ascertain the point. The key of Joan’s flat was at the Yard, and twenty minutes later he had obtained it and was in a taxi bowling towards Horne Terrace.

He kept the vehicle while he ran up the ten flights to No. 12 and secured the camera. Then hastening down, he was driven back to the Yard.

By a piece of good luck he found a photographer who had been delayed by other important work, and him he pressed into the service forthwith. With some grumbling the man returned to his dark room. French, too eager to await his report, accompanying him.

A few moments sufficed to settle the question. The camera contained a roll of films of which the first seven had been exposed, and a short immersion in the developer showed that numbers 5, 6, and 7 bore the hoped for impress.

Gone was French’s despondency and the weariness caused by his heavy day, and instead he was once more the embodiment of enthusiasm and cheery optimism. He had it now! At last the secret was within his grasp! Of his ability to read the message, now that he was sure he had the genuine one, he had no doubt. He had always liked working out ciphers, and since he had succeeded in extracting the hidden meaning from the stock and share list which had been sent to the elusive Mrs. X in the Gething murder case, his belief in his own powers had become almost an obsession. He could hardly restrain his eagerness to get to grips with this new problem until the negatives should be dry and prints made.

The photographer was able to promise these for the following day, and till then French had to possess his soul in patience. But on his return from lunch he found on his desk three excellent prints of the document.

They were only half-plate size, or about one-third that of the tracing which had been given to Cheyne. He therefore instructed the photographer to prepare enlargements which would bring the document up to more nearly the size of the original. These were ready before it was time for him to leave for home, and he sat down with ill-controlled excitement to compare them with the document at which he had already spent so much time.

And then he suddenly experienced one of the most bitter disappointments of his life. To all intents and purposes the two were the same! There were the same circles, the same numbers, letters, and signs enclosed therein, the same phrase, “England expects every man to do his duty,” spaced round in the same way! The tracing had not been very accurately done, as some of the circles seemed slightly out of place, but the discrepancies were trifling, and seemed obviously due to careless copying. He gave vent to a single bitter oath, then sat motionless, wrapped in the most profound gloom.