"Ferdinand!" gasped Jerce, and stretching out his hand, he gripped the young man by his overcoat collar. Before Baird could expostulate, he was drawn unresistingly along towards the light streaming from the open window, and Jerce was looking fiercely at his tall form and grey clothes. "Tell me why you knocked me down just now?" demanded the doctor, much ruffled, and short of breath. Ferdinand started back in genuine surprise. "I knock you down?" he repeated. "Why, doctor, you must be out of your senses. Why on earth should I knock you down?" "To search my pockets for some reason." Baird laughed at the monstrous charge. "Do you accuse me of robbery?" "Oh, no! You took nothing, but you searched me. Why?" and Jerce looked closely at the handsome, weak face of the spruce young gentleman. "But that you are a rabid teetotaler, doctor," said Ferdinand, with a shrug, "I should think you had been drinking. I have been for the last hour at the vicarage seeing Prudence, and before that I visited Mrs. Dumps' Savoy Hotel to look up the last train to town to-night. I have just returned, and you accuse me of assaulting you. It's too ridiculous!" And Baird, annoyed at being kept standing in the cold, began to fume like a spoilt child. "I tell you, Ferdinand, that you knocked me down, here--where we are standing, and searched my pockets thoroughly. I recognise you by the grey overcoat you are wearing, although you were clever enough to hide your face." "Grey clothes, eh?" mused Ferdinand, slowly. "There may be something in what you say, after all. A tall man in grey clothes, hat and all, passed me in the High Street, near Grinder's shop." "Did you see his face?" asked Jerce, doubtfully. "Yes. I don't usually take notice of a man's face, but this chap was a stranger here, and looked like a Londoner. He had a lean face, so far as I could see--yes, and a small black moustache. And--and,--oh, yes, doctor, there was a criss-cross scar on his cheek, I fancy. But, of course, he passed too quickly for me to observe him closely." "A scar on his cheek," said the doctor, loosening his grip. "Humph! I congratulate you on your rapid powers of observation. Only a woman could have gathered so much in one moment. I ask your pardon, Ferdinand. Doubtless, it was this fellow who knocked me down." "And here," Ferdinand looked round, "in our grounds. What cheek. I expected he wished to rob you." "If so, he certainly did not fulfil his intention, even though he had me at his mercy," said Jerce, dryly, and stepped into the room. "Shall I go for the police, doctor?" "No. We'll say no more about it, my boy." "Do you know this man?" asked Baird, puzzled. "I fancy I do, if you describe the scar accurately." "Oh, it was a criss-cross scar, right enough. But if he did not rob you, or wish to rob you, why did he go through your pockets." "That," said Jerce, with emphasis, "is as much a mystery to me, as it is to you." CHAPTER III TWINS