The Adventures of Sexton Blake!
Well, perhaps not that much of a mystery. In fact, as David Quantick explained in a Radio 2 documentary (still available to listen to for a few more days), Sexton is "one of the most famous and long-lived fictional detectives and adventurers of all time, a legend who battled opium smugglers, bandit chiefs albino fiends and the Kaiser. The missing link between Sherlock Holmes and James Bond".
So he is, or rather was once upon a time, a well-known fictional figure - a British action-sleuth who appeared in comics, books, television serials, feature films, radio plays. Now he's being resurrected in comedy form for Radio 2, played by The Hitchhiker's Guide's Simon Jones with a great supporting cast of Wayne Forester and June Whitfield.
But apart from the great cast and semi-legendary status of the character, perhaps the most exciting thing about this new series (for me, at least) are the duo who wrote it: funny novelist, Guardian columnist and author of Things My Girlfriend and I Have Argued About Mil Millington, and the curiously secretive Jonathan Nash - infamous videogame journalist - who along with Mil created the hilarious Weekly website. It might not sound it, but this is high pedigree indeed.
Most interesting of all, in this interview about the series Mil claims never to have met Mr Nash during the decade he has written with him:
He definitely does exist though.
The Adventures of Sexton Blake begins tonight at 9.15pm on BBC Radio 2. Find out more on the Perfectly Normal Productions website.