One evening in the January of 1745, the critical year of Fontenoy and of the great Jacobite rising, a middle-aged gentleman, the private secretary of a Secretary of State, was working as usual in the room of a house in Cleveland Row. The table at which he sat was littered with papers, but at this precise moment he had leaned back in his chair with a puzzled expression and his left hand in perplexity pushed his wig awry. “Extraordinary,” he muttered, “most extraordinary.” The remark was apparently caused by an official letter in his other hand--a letter marked “Most Private,” which came from The Hague, and the passage which he had just read ran: “I have the honour to submit to you the following important communication in cipher, received, through our agent at Paris, from ‘No. 101,’" etc. On the table lay the cipher communication together with a decoded version which the secretary now studied for the third time. In explicit language the despatch supplied detailed information as to certain recent highly confidential negotiations between the Jacobite party in Paris and the French King, Louis XV., a revelation in short of the most weighty state secrets of the French Government. “‘No. 101,’” the secretary murmured, scratching his head, “always ‘No. 101.’ It is marvellous, incredible. How the devil can it be done?” But there was no answer to this question, save the fact which provoked it--that closely ciphered paper with its disquieting information so curiously and mysteriously obtained.“Ah.” He jumped up and hurriedly straightened his wig. “Good-evening to you.” The new-comer was a man of about five-and-thirty, tall, finely built, and of a muscular physique, with a face of considerable power. Most noticeable, perhaps, in his appearance was his air of disciplined reserve, emphasised in his strong mouth and chin, but almost belied by the glow in his large, dark eyes, which looked you through and through with a strangely watchful innocence. “There is work to be done, sir?” he asked as he took the chair offered. “Exactly. To-day we have received most gratifying and surprising information from our friend ‘No. 101’--and we have the promise of more.” “Yes.” The brief monosyllable was spoken almost softly, but the dark eyes gleamed, as they roamed over the room. “The communications from ‘No. 101’ have begun again,” the secretary pursued; “that in itself is interesting. The Secretary of State therefore desired me to send at once for you, the most trustworthy secret agent we have. In a very few minutes Captain Statham of the First