Before watching, I heard nothing about this great little British shocker from (Tom Shanland - the guy who gave us the muddled but kinda entertaining Thriller WAZ).
Two familys come together in a remote country home to celebrate Christmas unbeknown to them that their children are infected with some vague/unexplained virus that turns the tots in psychotic killers.
Despite the mostly unlikable bunch of characters (Rich Twat 30-somethings), the acting is remarkably strong and combined with some great editing (particulary the sound) create a atmospheric and slowly climatic descent into horror as the Adults realise that the danger is not only awong them but the threat is from their very offspring..
The violence is strong, realistic and cringeworthy with the added taboo of much of it being perpetuated against minors much like the also excellent 'Who would kill a child?'..
I'd definally recommend this suprising little low budget rural English horror..