Newton Moore is an agent with the British Secret Service Fund.
Exactly why the department is called a "fund" is not mentioned but looking up the definition of the word shows that it can mean something "saved or made available for a particular purpose", in this case espionage. It also could mean a "large stock or supply of something" as in a "fund of information". Either explanation would fit and together they make sense as well.
This intelligence organization works out of the Foreign Office and its personnel have considerable authority throughout the country and have responsibility for many things happening outside the borders. It is directed by the austere Sir Gresham.
In addition to being the best operative the group has, Moore is a novelist with a good deal of success, his books being known not only in England but also throughout Europe. His ability to pen interesting stories has worked against him, though, as he is said to be a man "cursed with a vivid imagination, and unseen terrors always unmanned him." In fact, in a passage in the first recorded adventure, "he had described himself as a coward, who was a hero in spite of himself. His imagination magnified the unseen danger, but the same fine inventiveness taught him the right moment to strike." As time passes and other missions are told, his "cowardness" is largely forgotten though he does retain a healthy discretion.
He is a slight man with a retreating hairline leaving a pronounced widow's peak and he routinely wears a pince-nez. He is shown in illustrations in the magazine to have a very narrow pointed chin and a sharp thin nose. Clean shaven, his sideburns reach the top of his earlobes. The actual tales say little about his looks, though.
The success that Moore has had as a novelist and possibly an inheritance allows him to live rather well. He has a nice set of apartments in London and has a manservant named Painter who is an ex-sergeant in Scotland Yard's CID. The latter does not get involved much, however, in Moore's cloak and dagger escapades.
Moore boasts he knows "all the little bands of scoundrels who are on this game" as well as "quite au faut with every foreign ruffian in England." His inventiveness comes in handy on several occasions and his gift for planning is well known. "The fox had a dozen ways of escape from the hounds, and fell into their jaws at last. The cat had one avenue and escaped by it. Moore's method must be like that of the cat." it is said in one passage.