THE old saying ‘the show must go on’ is particularly appropriate for one theatre production this Christmas.

Actor Mark Gatiss has had to withdraw from the Hampstead Theatre’s Christmas production, Darker Shores, at the last minute, following the serious illness of a close family member.

Gatiss, best known for roles in The League of Gentlemen and Doctor Who, was due to star in Michael Punter’s Victorian ghost play, but he has now been replaced by Tom Goodman-Hill.

Tom, who joined the cast during technical rehearsals, has just completed a run as Andy Fastow in Enron at the Royal Court. His other credits include Spamalot in the West End, The League of Extraordinary Gentlemen, The Office and Hustle.

Anthony Clark, artistic director of Hampstead Theatre and director of Darker Shores, says: “Our thoughts are with Mark, who is currently with his family. We are very sad that his hard work and talent will not be seen on stage in this production.

“However, we are very fortunate to have Tom joining the cast at the eleventh hour. We are confident that he will bring an equally special quality to the role.”

The cast of Darker Shores also includes Julian Rhind-Tutt (Green Wing) Pamela Miles and Vinette Robinson.

Set at Christmas, 1875, Darker Shores tells the story of Professor Gabriel Stokes (Tom), who retreats to the house by the sea, an old family haunt on the desolate Sussex coast. No sooner has he arrived than his peace is disturbed by mysterious goings-on.

He enlists the help of a flamboyant American spiritualist, Tom Beauregard (Julian Rhind-Tutt), and the two embark on a terrifying journey to discover the true history of the house.

Darker Shores is the last play in Hampstead Theatre’s Anniversary year and marks Anthony Clark’s final production as artistic director.

He will step down in January after seven years at the helm.

Darker Shores runs until January 16. Tickets: 020 7722 9301 or (£15-£25).