Inspector French had just completed these arrangements when a cable was handed to him. It was in reply to his of the previous night, and read:

“Mrs. Chauncey S. Root, Hotel Bellegarde, Mürren, till end of month.”

Mürren? That was in Switzerland, wasn’t it? He sent for an atlas and a Continental Bradshaw, and looked it up. Yes, it was in Switzerland; moreover, it was close to where he had already been, past that lake with the marvellous colouring—the Lake of Thun, and so to Interlaken and the far-famed Bernese Oberland, places which he had long desired to visit. It was with more than a little eagerness that he once more ran over his reasons for wanting to see Mrs. Root, and then, satisfied, went to his chief’s room. The great man listened and was convinced, and French, jubilant, went to prepare for his departure on the following evening.

On his way to the Yard next morning, he called at the White Star offices and got a copy of the Olympic’s passenger list of the trip in question. The ship, they told him, was in New York, but would be sailing in another three days. She would therefore be due in Southampton on the following Wednesday week.

He learned also that specimens of the handwriting of each traveller were available. Forms were filled and declarations signed both in connection with the purchase of the ticket and with the passing of the luggage through the customs. If French was anxious to examine these, he could do so by applying to their Southampton office or to the customs authorities in the same city.

French decided that if his interview with Mrs. Root led to nothing, he would follow this advice, and he resolved that in this case he would go to Southampton when the Olympic was in, so as to interview the ship’s staff as well.

When he returned to the Yard, he found that some information had already come in about the jewellery. One of his six plain-clothes men had had a stroke of luck. At his very first call, Robsons’ of Oxford Street, he had found a ring which answered the description of one of the purchased articles, and which had been bought from a lady on the afternoon of the day after that on which Mrs. X had opened her bank account. He had taken the ring to Messrs. Lewes & Tottenham, who had made the sale in question, and they identified it as that sold to Mrs. X and paid for by a Mrs. Root’s cheque. Robson had paid £190 for it, while Messrs. Lewes & Tottenham had charged £225, so the lady had lost rather badly over the transaction. She had taken her money in notes of small value, the numbers of which had not been observed.

The assistant at Robsons’ who had served Mrs. X could not recall her appearance; in fact, it was only when confronted with the records of the purchase that he remembered the matter at all. But he was satisfied the client was an American lady, and he thought she was neither very old nor very young, nor in any way remarkable looking.

Inspector French was delighted with his news. It proved to him beyond possibility of doubt that his theory was correct. The purchase of these jewels was simply part of the plan to turn the stolen diamonds into money in a form which could not be traced. Further, it showed that he had also been right in assuming the lady had not gone to France on the evening she drove to Victoria; on the following day she was still in London.

But so far as he could see, the discovery brought him no nearer to finding the mysterious woman. The dealer’s assistant could not describe her, nor had she left any traces which could be followed up. In fact, here was another promising clue which bade fair to vanish in smoke, and as he thought over the possibility, some measure of chagrin began to dull the keenness of his delight.