Flynn was arguing something, emphasising his words with his hands, while Langton stood by listening in silence. Then there was the sudden movement of the porters who had noticed some signal fall, and looking towards the dark bridge I saw the headlight of the engine slowly approaching. The doctor raised his finger to his friend, an action expressive of an injunction of silence. Whom were they expecting to arrive? With bated breath I stood motionless, watching in eager wonder. From the arrival, whoever it might be, these men intended to preserve some secret. CHAPTER TWENTY ONE. I MAKE A BOLD MOVE. For a moment I lost the two men in the excited crowd of alighting passengers, but when I gained another sight of them, my heart stood still. Talking with the pair was a well set-up, alert man whose back was turned to me--a man in a soft grey felt hat and heavy travelling coat with beaver collar. Both men were speaking quickly, eagerly, telling the new-comer something of an urgent nature, being hustled at the same time by the bustling passengers eager to claim their luggage from the Customs barriers, and get away. I moved a little distance along, recognising in the man just returned from the Continent the grey, thin, sinister face of Kershaw Kirk. My first impulse was to rush forward and demand of him the truth; indeed, to charge him with a secret crime, and to insist on knowing the whereabouts of my beloved Mabel. But it struck me at that instant that the two men who had met him had agreed between themselves upon a course of secrecy, and that they were therefore misleading him. Had not Ethelwynn already told me of Langton's suspicion of this man, who was to me and mine such a mystery? Therefore I held back for the moment, awaiting my opportunity. Standing beyond the barrier where the baggage was being sorted, ready for the Customs examinations, I watched the trio from my unseen point of vantage. I doubt that either would have recognised me in those greasy mechanic's clothes of mine. Within myself I felt a sense of complete satisfaction. Kirk had returned to England, and was therefore now within the jurisdiction of the law, however much he might pretend to be immune from its penalties. What Flynn was saying evidently caused him to hesitate. He was thoughtful for a single moment, but next second shrugged his shoulders, with a gesture of disregard. A taxi drew up close to where I stood, and I engaged him, telling him to wait. To my satisfaction I saw it was the same driver who had brought me along from Piccadilly. Then, as I watched, I saw something which caused me to reflect. A porter, quickly recognising Kirk, took from him his baggage ticket and foraged out a big, battered kit-bag which had been placed upon the bench ready for the argus eye of his Majesty's Customs. The porter uttered a word to the revenue officer and pointed to the bag, whereupon the officer chalked it without opening it.