Neverwhere's story revolves around Londoner Richard Mayhew, whose life as he knows it ends swiftly -- and somewhat unexpectedly -- when he tries to help a hapless stranger and immediately ceases to exist in the mortal world, joining the citizens of London Below.
Co-creator Gaiman recently revealed via his blog how the project came to be:
"(It'll start on Radio 4 and then go over to Radio 4 extra.) The adaptation is by Dirk Maggs, who did the last three Hitchhiker's Guide Radio adaptations. He's co-directing it with producer Heather Larmour, who is the one who went off and made this happen after a small enthusiastic chat in a London coffee shop much earlier this year -- the kind of conversation that you have that normally just leaves you feeling happy, but doesn't actually turn into anything real. This time it did."
A 15th Anniversary Edition DVD of Neverwhere was released a year ago.