This complicated matters considerably. It would have been comparatively a simple matter to follow a motor-car, but to hang behind a motor-omnibus in such a way that they could, without being noticed themselves, see if Patmore left it, was a more difficult piece of work altogether. Their anxiety was considerably lessened when the motor-car drew up at the further end of Holborn viaduct. They saw Patmore leave it and jump into a waiting taxicab. The taxicab shot straight ahead up Holborn, and from the fact that Patmore had not troubled to look about him Westerham judged that he was not anticipating pursuit. The taxicab, which they kept well in view, ran quickly through Oxford Circus and on to Orchard Street; there it turned north, and they followed it as closely as they dared past Baker Street to St. John's Wood Chapel. As it shot ahead up the Finchley Road, Westerham wondered whether Patmore was making for Mme. Estelle's. He decided, however, that this could scarcely be, as he had taken the precaution of having the house closely watched throughout the day, and up to the time he left Downing Street there had been no report as to the return of any of its wonted inmates. Soon, too, it became apparent that Laburnum Road was not the goal. The taxicab rushed past Swiss Cottage and on to Finchley. Here it branched off to the north, and finally turned up a newly laid-out road. Westerham called to Lowther to pull up at the corner, as he knew their destination must now be in sight. So certain was Westerham that they were now nearing the goal that he left the car and walked on foot to the corner of the road. Just as he imagined would be the case, the taxicab had drawn up outside a neat, brand-new, red-bricked villa. He dodged round the corner again, and hastily, lifted the car's bonnet. He called on Lowther to get down, and together the two men began to examine a sparking plug with wholly fictitious energy. The returning taxicab passed them at a good pace, the driver paying no heed either to them or to the car. Westerham took a deep breath and withdrew his head from the covering bonnet. “Come along, Lowther,” he said, “I fancy that the last act is about to begin. “I wonder,” he added more to himself than to his companion, “whether Lady Kathleen is here?” As he paused at the gate he clapped his hand to Lowther's hip-pocket and nodded with approval. “Loaded?” he asked. Lowther nodded. “All right,” he said; “you may need it, but we will go quietly to start with. I am going in first. If I don't appear in five minutes come in after me, and don't stick at trifles. I may want you before then, and if I do I will give a sharp whistle, so——” He rehearsed the whistle under his breath. Lowther signified his understanding, and stepped back into the shade of one of the brick pillars of the gate as Westerham swung into the garden and ran quickly on silent feet up the steps.