"Easily explained, constable. You have a parcel under your arm. It has been crushed. The brown paper covering has burst. I can see a portion of the contents: a boy's cap with the badge of Collingwood College. Since one of my pupils--this lad, as a matter of fact--has arrived without a cap, coat or boots, and has reported to me that he jumped into the Thames after a gentleman who was thrown over the bridge by a couple of roughs, it naturally follows that I can guess the nature of your errand." "You are quite right, sir," said the constable, admiringly. "I frequently am," rejoined the Head, complacently. "But to return to the point: has the identity of the victim been established?" "Yes, sir, the gentleman is Sir Silas Gwinnear. You might have heard of him, sir." Leslie Trematon gave an exclamation of surprise. Atherton, equally astonished, could hardly realise the news. It seemed like a dream. Only a few days previously Sir Silas had written expressing his opinion of the Scout movement in emphatic terms of disapproval, and now, by the irony of fate, he owed his life to a Scout's promptitude and bravery. "What is the matter, Mr Trematon?" asked the Head, who could not fail to notice the Scoutmaster's ejaculation of astonishment. "I happen to know Sir Silas, sir," he replied. "He was a friend of my father's. Only the day before yesterday he wrote to me." "And how is Sir Silas?" asked the Rev. Septimus, addressing the policeman. "Getting along finely, sir, considering he's not a young man by any means." "And his assailants?" "No trace of them, sir. One of our men found these articles of clothing and took them to the station. A letter addressed to Master Atherton was in one of the pockets, so the Inspector sent me here to make enquiries. Is this the lad, sir?" "That is Atherton, constable." "Look here, young gentleman, can you give us any information as to what occurred?" The Scout accurately described the appearance of the two men whom he saw commit the assault. The policeman, hardly able to conceal his surprise at the detailed description, laboriously wrote the particulars in his notebook; the Head was also surprised at his pupil's sense of perception. Only Mr Trematon maintained a composed bearing. Inwardly he was proud that his instruction in scoutcraft had borne such good fruit. "Let me see," remarked the Rev. Septimus. "Atherton is, I believe, a--er--Scout?" "Yes, sir," assented the Scoutmaster. "He ought to be a detective, sir," observed the constable. "Only it's a great pity he didn't inform us at once. We might have nabbed those rascals." "He quite realises that," said the Head. "One thing, he has been the means of saving life under very trying circumstances. The capture of the assailants is, after all, a secondary matter. Trematon, you ought to be proud of your Scouts if they are all like this one." "I trust they will prove themselves equal to the occasion should necessity arise, sir," replied the Scoutmaster.