The Snowmen: new trailer/synopses

Christmas Eve 1892, and the falling snow is the stuff of fairytales.

When the fairytale becomes a nightmare and a chilling menace threatens Earth, an unorthodox young governess, Clara, calls on the Doctor for help. But the Doctor is in mourning, reclusive and determined not to engage in the problems of the universe. As old friends return, will the Doctor really abandon humankind or will he fight to save the world – and Christmas – from the icy clutches of this mysterious menace?

Starring Matt Smith, Jenna-Louise Coleman, Richard E Grant and Tom Ward.

Executive producers - Steven Moffat and Caroline Skinner; produced by Marcus Wilson; written by Steven Moffat.

1892: snowfall is making for a picture postcard Christmas Eve, but a chilling menace threatens Earth as an unorthodox young governess, Clara, calls on the Doctor for help. He, however, is in mourning, reclusive and intent on ignoring the problems of the universe.

Cast: The Doctor - Matt Smith; Clara - Jenna-Louise Coleman; Dr Simeon - Richard E Grant; Strax - Dan Starkey; Jenny - Catrin Stewart; Vastra - Neve McIntosh; Captain Latimer - Tom Ward; Alice - Liz White; Digby - Joseph Darcey-Alden.

Writer Steven Moffat; Producer Marcus Wilson; Director Saul Metzstein.

It's a snowy 1842 Christmas and a little boy is building a snowman. Ah, how sweet. But forget Walking in the Air, this snowman is a monster made from telepathic snow. Fifty years later, snowmen with big teeth are breeding, ready to take over the world at the behest of a madman and his huge talking glass globe. Only the Doctor can save the planet, but he's a shadow of his former self after past tragedies. Alone and bereft, he's roaming the galaxy in a new-look TARDIS where unhappiness is his only friend. Until he meets twinkly barmaid/governess Clara.