"But robbery being established as the motive of the outrage did not greatly help matters, because, while Mr. Stonebridge remained in such a helpless condition, it was impossible to ascertain what booty his assailant had carried away. Soon, however, the first ray of light was thrown upon what had seemed until this hour an impenetrable mystery. "It appears that Mr. Medburn was looking after the business in High Street during his employer's absence, and one morning--it was on the Monday following the night of the outrage--he had a visit from a client, who sent in his name as Felix Shap. The head clerk knew something about this client, who had recently come over to England from somewhere abroad, in order to make good his claim to certain royalties on what is known as the Shap Fuelettes--a kind of cheap fuel which was launched some time before the War by Sir Alfred Carysfort, Bart., of Tytherton Grange, and out of which that gentleman made an immense fortune, and incidentally got his title thereby. "This man, Shap--a Dutchman by birth--was, it appears, the original inventor and patentee of these fuelettes, and Mr. Carysfort, as he was then, had met him out in the Dutch East Indies, and had bought the invention from him for a certain sum down, and then exploited it in England first and afterwards all over the world at immense profit. Sir Alfred Carysfort died about a year ago, leaving a fortune of over a million sterling, and was succeeded in the title and in the managing-directorship of the business by his eldest son David, a married man with a large family. The business had long since been turned into a private limited liability company, the bulk of the shares being held by the managing-director. "The fact that the patent rights in the Shap Fuelettes had been sold by the inventor to the late Alfred Carysfort had never been in dispute. It further appeared that Felix Shap had at one time been a very promising mining engineer, but that in consequence of incurable, intemperate habits he had gradually drifted down the social scale; he lost one good appointment after another until he was just an underpaid clerk in the office of an engineer in Batavia, whose representative in England was Mr. Alfred Carysfort. The latter was on a visit to the head office in Batavia some twelve years ago when he met Shap, who was then on his beam-ends. He had recently been sacked by his employers for intemperance, and was on the fair way to becoming one of those hopeless human derelicts who usually end their days either on the gallows or in a convict prison. "But at the back of Shap's fuddled mind there had lingered throughout his downward career the remembrance of a certain invention which he had once patented, and which he had always declared would one day bring him an immense fortune; but though he had spent quite a good deal of money in keeping up his patent rights, he had never had the pluck and perseverance to exploit or even to perfect his invention.