Forget warmth, carols, and Christmas cheer — this year, the BBC is giving viewers something far darker. Acclaimed writer-director Mark Gatiss returns with his most chilling Christmas ghost story yet: The Room in the Tower, starring Tobias Menzies and Dame Joanna Lumley in a haunting tale that’s already being hailed as “utterly nightmarish.”

The story follows Roger Winstanley (Menzies), a man haunted for 15 years by the same recurring dream — a mysterious invitation to a grand English country house where nothing is as it seems. Time bends. Guests appear and vanish. Familiar faces grow old before his eyes. And always, in the shadows, waits the cursed Room in the Tower, a place whispered about but never entered… until now.

Filmed at the atmospheric Cobham Hall in Kent, the production radiates gothic elegance and creeping dread. The cast — including Nancy Carroll, Ben Mansfield, and Polly Walker — brings both refinement and terror to Gatiss’s elegant horror. But it’s the pairing of Menzies’s tormented subtlety and Lumley’s icy grace that steals the show.

Fans of Gatiss’s previous ghost stories — Lot No. 249, Count Magnus, and Martin’s Close — are already calling The Room in the Tower his most ambitious and frightening work yet. Blending Edwardian unease with psychological horror, Gatiss once again captures that uniquely British chill: fear not from monsters, but from memory, silence, and things best left undisturbed.

Early reactions from BBC insiders describe the film as “a slow, elegant descent into madness.” The atmosphere, they say, is thick with dread — every candle flicker, every creaking floorboard, every breath echoing like a warning from beyond.

As the Christmas season fills with joy and light, Gatiss offers something colder: a tale that freezes the blood and crawls under your skin. The ghosts of Christmas, it seems, have never been this cruel — or this unforgettable.

“The Room in the Tower” airs this Christmas on BBC Two and iPlayer. But be warned — after watching, you might think twice before falling asleep…