At last they descended together into the street, and at the corner of Oxford Street entered into a taxi-cab in which they drove back to Notting Hill Gate station.

There he raised his hat as she descended and hurried across into Pembridge Gardens, while he gave the man directions to return to his own chambers.

“By Jove!” he exclaimed, aloud, as they went along the Bayswater Road with the horn “honking.”

“The whole situation is now a terribly complicated one. To throw in my lot with the Professor and his daughter would mean a ‘stretch’ for me, without a doubt. Challas is vindictive, because I allowed her to escape from his infernal clutches. He meant to serve her the same as he did that poor young German girl! Hang me! I may be an outsider, but I’m not going to stand by and see another woman fall a victim. Now what is the best game to play in the interests of Griffin and Diamond? Stand by, watch old Erich, and if he gets hold of anything tangible, give it to them at once. That’s the only way that I can see. Yet—yet I may already be suspected of playing a double game—and if I am, it means that I’ll be given away to the police at the first opportunity. No,” he added with great bitterness, “in this game Felix Challas and Jim Jannaway hold all the cards. Money talks here, and it does always,” he sighed.

And he sat back in his cab in a deep reverie. Already he was tired of London, though he had not set foot in it for three years. He was too near Challas. When absent on the Continent, he simply obeyed orders, and led the easy-going life of the cosmopolitan concession-hunter, always well-dressed, always apparently flush of money, always merry and prosperous-looking, and always outwardly, at least, presenting the appearance of a gentleman.

Here, in London, however, he was simply the cat’s-paw of an unscrupulous parvenu who cloaked his evil doings beneath the remarkable sanctity and generous philanthropy.

“It’s a blackguardly shame that poor little Gwen, a smart little girl and yet sweet and innocent as a child, should be parted from her lover like this!” he went on, still murmuring to himself. “No doubt this man Farquhar, whoever he is, doubts her. I’d do the same if the girl to whom I was engaged ran away from home, stayed away a few days, and then on her return refused to give any account of herself. Frank Farquhar isn’t a fool, and I admire him for that. I’m to blame for the whole thing,” he added with a bitter imprecation, “because I’m a coward and fear nowadays to face the music. Yes,” he went on, “Red Mullet is in fear of his enemies! It’s no good denying it. Hitherto he’s always defied them, even at the muzzle of a gun! But recently they’ve become just one too many for him!”

He paused and lit a cigarette. Then with a sudden gesture of despair he asked himself aloud: “How can I assist the little girl to get back her lover? Frank Farquhar is a good fellow, I’ve discovered. And he’s devoted to her. How can I compel him to believe in her?”

When he entered his chambers, he flung himself again into the armchair in which Gwen had sat.

“It would be a cursed shame if ever the sacred relics of Israel fell into the hands of such a blackguardly hypocrite as Challas. What does he care for their antiquity, or their religious significance? Nothing. The gold he’d melt down and sell at its market value per ounce, while the sacred objects of the Holy of Holies he would wantonly destroy, in face of the Jews and in order to laugh them to scorn. He shan’t do that! By Heaven! he shan’t. If the treasure is still there it shall be recovered by the Doctor and Griffin. I’ll help them, and I’ll still remain little Gwen’s protector, even if it costs me my liberty to do so. Besides—”