"How do you know, my dear fellow?" he asked.
"For the simple reason that I was there," I laughed.
He looked astounded.
"I remember the report on the Cromer mystery, last June, perfectly well," he said. "But I never dreamed that you'd taken the matter up. We shall certainly do well if we can lay hands on Jeanjean, for we get constant reports from Paris about his wonderful exploits. I had one only this morning. He is suspected of having done a big job at a jeweller's in St. Petersburg, lately."
"Very well," I answered. "Let us take a taxi up to Arkwright Road at once. Benham, your ex-sergeant, is already there awaiting us, as well as my servant, Rayner."
Together we entered the next room, where Craig and Lola were sitting closely together, and I introduced them to the well-known Chief Detective-Inspector. Then, after Sommerville had telephoned to his office, and ordered up to Hampstead three of his men, we waited for another quarter of an hour to give them time to get to the appointed spot—the public-house in the Finchley Road.
At last we started, and on the way I explained many facts to my old friend Sommerville, who, with a hearty laugh, said—
"Well, Vidal, I know you're pretty painstaking over an inquiry, but I never thought you'd ferret out this great French jewel-thief when we had failed! Of course, we've looked upon this man Vernon with suspicion for some little time. He sold some stolen rubies in Antwerp two months ago, and it was reported to us, but we couldn't get sufficient evidence. I made some inquiry, and found that he's immensely wealthy, although he lives such a changeful life. The house in Arkwright Road is his, but he is never there more than two or three days at a time. He experiments in wireless telegraphy, judging from the masts and wires in his back garden."
I told him of Jeanjean's powerful station in Algiers, and we agreed that, by means of a code, the pair were in the habit of exchanging messages, just as Jeanjean did with his confederate in Genoa.
"Yes," Lola said. "At Merton Lodge there are big dynamos down in the cellars, and when I've been with my uncle at the Villa Beni Hassan, he has often come from the wireless room and told me he has been speaking with his friend Vernon in London. Wireless telegraphy is wonderful, is it not?"