Good Omens follows the attempts of an angel and a demon (Heap and Serafinowicz) to save the world from the antichrist, but all is not as it seems thanks to a bureaucratic mix-up. Soon, the fate of humanity is left to a gang of young children, a trainee witchfinder (Morgan) and a collection of garbled flashcards.
It was written by Gaiman and Pratchett in 1990, and became a bestseller that remains popular to this day. Now, the two writers have joined up with the team behind the 2013 smash-hit radio adaptation of Gaiman's book and TV series Neverwhere which starred Benedict Cumberbatch, James McAvoy, Christopher Lee and Natalie Dormer.
Gaiman (who appears in the promotional photos) has assisted returning Neverwhere director and adaptor Dirk Maggs with the scripts, and both he and Pratchett will make cameo appearances alongside the main cast.
RadioTimes.com caught up with the drama's star Colin Morgan who explained, despite appearances, you won’t find a better listen for the festive season...
“It’s about the antichrist, at Christmas – nothing more festive that that!” said the Merlin and The Fall actor.
“But it’s got heart and the soul. It’s the escapism, the fantasy element of it, the charm and magic that surrounds Christmas, I think. And it’s pure escapism.
He added: "I think everybody can get something from it. I think fans of Terry and Neil will be extremely pleased.”
Good Omens will begin on Radio 4 on Monday 22nd of December at 11.00pm