Though nearly six o'clock in the morning, it was quite dark, but as Brett walked rapidly back towards the station he had no difficulty in picking out Gaultier, who occupied an open vehicle. Some little distance behind came another, and herein the barrister thought he recognized the man to whom the Frenchman in the train had spoken. By this time many other cabs were dashing out of the station-yard, so Brett took the chance that he might be hopelessly wrong. He hailed a third vehicle and told the driver to follow the other two, which were now some distance down the Rue Lafayette. Not until the three cabs had crossed the Place de l'Opera and passed the Madeleine could Brett be certain that the occupant of the second was following his friend Gaultier. Then he chuckled to himself, for this was surely a rare stroke of luck. Quickly reviewing the possibilities of the affair, he came to the conclusion that the travelling Frenchman really understood little, if any, English, but that he had caught the name of the fugitive from the Sultan's wrath and had forthwith betrayed an interest in their conversation which was, to say the least, remarkable. At the exit from the Gare du Nord the stranger had readily enough ascertained Brett's destination, but he clearly regarded it as important that Gaultier--the man who claimed Hussein-ul-Mulk as a friend--should be tracked, and had given the necessary instructions to the confederate who awaited his arrival. Although Gaultier had not said as much, Brett guessed that his destination was the British Embassy in the Rue du Faubourg St. Honoré. The route followed by the cabman led straight to that well-known locality. The Frenchman in the second cab evidently thought likewise, for, at the corner of the Rue Boissy he pulled up, and Brett was just in time to give his driver instructions to go ahead and thus avoid attracting undue notice to himself. Gaultier turned into the Embassy, and Brett himself halted a little further on. Dismissing his _cocher_ with a liberal fare, he walked rapidly back, and saw the spy enter into conversation with the night porter on duty. The latter personage, however, was clearly a trustworthy official, for he loudly told the other to be off and attend to his own affairs. Then followed a most exciting and perplexing chase through many streets, and it was only by the exercise of the utmost discretion that Brett finally located his man at a definite number in the Rue Barbette, a tiny thoroughfare in the Temple district.