Barnabas Hildreth is an agent with the British Secret Service.
He is also known to many as The Black Monk, a sobriquet which is used in the first several adventures and then apparently never again. The nickname was likely given due to his countenance on many occasions, described by one newspaper reported as: "he looked haggard, as though from fasts and long disciplines. His features seemed lit by that goblin fire one finds inherent in the matt-white flesh of woodland fungi.... A curiously unhealthy apparition altogether".
Add to that this not-so-complimentary fact that the narrator "found the fellow extraordinarily clusive [unconcerned and off the grid]. He had cat habits of an insolent sort: among them the silent adroitness of making himself scarce at a second's notice. From all I could gather, Hildreth was an utterly friendless man simply because he did not choose to admit - again like the cat - that there is much room in this wide earth for two, walking abreast". On the other hand, that same chronicler waxed positively poetic wit "The rich slow voice had a curious and passionate tenderness ...I looked down into luminous and patient brown eyes abnormally deep-set in a lean and pallid face which was almost that of a saint".
An Under Secretary of State said when inquired about Hildreth, "A chap best left alone. Hildreth's just too dangerous an enigma for most people." A Cabinet Minister commented, "An eccentric cuss if ever there was one; half-poet, half-scientist, maybe genius." Both statements were said off-the-record because as far as the Press was concerned, the government considered Hildreth as 'tabu'! With regards the department for which he works, it is said of Hildreth that he possessed "deadly acumen and dispassionate skill frightened even the Secret Service mandarins who employed him from Whitehall!"
We do not see Hildreth involved in many cases where his work would be actually associated with espionage; most of the cases that fall into his lap or is brought to him are criminal in nature. This then puts much of his work directly in the realm of the Britain's C.I.D. which over the years has learned that Hildreth is a valueable resource but one they find particularly irksome to have to make use of. This reticience is undoubtedly because Hildreth is not one of their own but instead "an officer of the Political Intelligence - otherwise the Secret Service".
The narrator of the adventures of Hildreth that we have is Geoffrey Ingram, a well respected and valued member of the Fourth Estate working for the Daily Post of London as both a reporter and, much later on, newspaper editor. To say that Ingram is on many occasions a most put-upon man by Hildreth is being mild to Hildreth and unfair to Ingram; many is the time that Ingram would be either hard at work or preparing to go to bed or packing for a vacation only to find Hildreth pop up unannounced and unbidden at his desk or front door insisting that Ingram drop everything to accompany Hildreth. Often it is to help uncover some obscure fact and more often, IMHO, to be present during a case's denouement to serve as witness to Hildreth's genius and cleverness.
Luckily for we readers and for the sake of Hildreth's ego forever in danger of overinflation, Ingram is ever ready to chide Hildreth enough to bring him back to reality once in a while - except for those times when Ingram is flabbergasted at the way Hildreth uncovers the truth and solves the latest mystery.
- About a client, Hildreth tells Ingram, "He's wanting me as a first-line defense. I'm to rake his chestnuts for him". [I'm thinking this is similar to 'pulling your chestnuts out of the fire' but I could be wrong.]