The six-part adaptation of "Neverwhere" for BBC's Radio 4 and Radio 4 Extra was re-released but it won't be available for long.

"Neverwhere" started out as a television series on BBC Two. After its run, it was adapted by Neil Gaiman into a novel of the same name, where he not only elaborated on the story's elements but also included some of his original ideas that didn't make the cut in the TV show.

The radio adaptation was first broadcast in March 2013 and re-released in December of the same year. The second release was a limited run that lasted just six days.

BBC once again made the six episodes available in February. This third run will last until March 27, the last day the sixth episode, "The Key," is accessible.

Episode 1, "London Below," will be available until March 22; episode 2, "Earl's Court," until March 23; episode 3, "The Angel Islington," until March 24; episode 4, "The Black Friars," until March 25; and episode 5, "Market Afloat," until March 26.

"Neverwhere" tells the story of Richard Mayhew and the day his ordinary life is turned upside-down, when he discovers London Below, the London beneath the London that he knows - London Above - after stopping to help an injured girl on the street.

In London Below, he meets an assortment of other characters, like the injured girl's companions, Hunter the bodyguard and the Marquis de Carabas. Mayhew will have to escape the clutches of assassins and help Door, the injured girl, discover who really had her family murdered, while finding a way to get back to his life in London Above.

The "Neverwhere" radio adaptation boasts a stellar cast that includes James McAvoy as Richard, Christopher Lee, Benedict Cumberbatch, Natalie Dormer, Sophie Okonedo, David Harewood, Anthony Head, George Harris, David Schofield, Bernard Cribbens, Andrew Sachs, Romola Garai, Lucy Cohu, Paul Chequer, Johnny Vegas, Abdul Salis and Don Gilet.