It was the foreign element in the League that gave rise to special uneasiness at the Home Office and Scotland Yard. Ere long the sense of insecurity already germinating in the public mind was greatly accentuated by a startling discovery, rumoured, though not yet proved, to be connected with the Leaguers’ campaign. This was nothing less than the unmasking by Detective-Inspector Henshaw of a dynamite factory, only seventeen miles from London. In all probability the discovery would never have been made but for a murder of revenge, almost unexampled in its cold and calculated deliberation, and in all respects notable in the annals of criminology. It was a story of the ruthless edict of a secret society within a society, and that society was believed to be none other than the League; it revealed, when the story became fully known, the remorseless execution of a mysterious mandate, which yet again illustrated the truth that, however subtle and well considered the plan of crime, murder, in the end, will out. The victim of the crime was one Grady, a doctor, who, after spending some years in New York, had come to England and acquired a fifth-rate medical practice in the purlieus of Holborn. His house and surgery were in Red Lion Street, not far from Red Lion Square. Grady was a man of ill-balanced mind, and given to intemperance. For some reason, never fully explained, he quarrelled with his friends. And, justly or unjustly, was suspected of betraying their plans to the police. The doctor became an object of hatred and fear in the eyes of his former associates, and the inner circle--or “actives,” as they were euphoniously styled--deliberately sentenced him to death. Early in June a man passing under the name of Featherstone took a room in the house facing that in which the ill-fated doctor carried on his miserable practice. Some articles of furniture and other things, including a large packing case, were bought by Featherstone and sent to his lodgings. At about the same time Featherstone, under the name Rolf, became the tenant of a house at Rickmansworth, which was let with a builder’s yard containing sundry sheds and outbuildings. Ostensibly these premises were to be used for the purpose of manufacturing Portland cement. At the end of the garden and yard ran the Grand Junction Canal. Close at hand was the River Colne; and in this way facilities were available to convey chalk and clay from a neighbouring estate to the “factory,” and to send the cement, when manufactured, on barges to London. Rolf, the “innocent manufacturer,” who was bent on developing this useful industry, advertised for a medical man to attend his workmen in case of illness or accident, and a marked copy of the paper containing the advertisement was sent to Grady. The doctor, compelled, doubtless, by his needy circumstances, swallowed the bait, and without much delay a contract was made with him on “club terms.”