A cast that includes James McAvoy (X-Men: First Class, Wanted) Benedict Cumberbatch (Sherlock, Star Trek Into Darkness), Natalie Dormer (Games of Thrones), Anthony Head (Buffy the Vampire Slayer) and Christopher Lee (Lord of the Rings, Star Wars) feels like a thing of nerd nirvana. Not only that, but they've all come together for a project written by none other than Neil Gaiman. So why haven't you heard more about this?

Probably because the project in question isn't a movie or television show, but a BBC radio series only available outside of the U.K. via the internet.

The series is an adaptation of Gaiman's Neverwhere, the story of one man's discovery of a magical city underneath London, England. It started life as a 1996 television series before becoming a novel (written by Gaiman in 1996, and later revised a couple of times), comic book series (adapted by Mike Carey and Glenn Fabry for the Vertigo imprint of DC Comics in 2005) and multiple stage plays. This time around, it's being being brought to life as an audio play for the BBC by producer and writer Dirk Maggs.

Audio plays are common in the U.K. but far from a mainstream in the U.S., though it's a format that may be undergoing a ground roots revival online thanks to podcasts like the Thrilling Adventure Hour and Decorder Ring Theatre. Maggs is a smart choice for the format; his radio resume is almost impeccable, with shows based on the works of Douglas Adams, Spike Milligan and the Goons and the Marx Brothers amongst many others, and he has multiple awards under his metaphorical belt on both sides of the Atlantic for his work throughout the years.

The series already has three half-hour episodes available online, with three more to come. All episodes will be made available internationally to stream via BBC's Radio iPlayer until March 29.