Christmas is a season of overindulgence. For most of us, that means an extra mince pie, a second helping of turkey, or perhaps a third glass of mulled wine. But for some among us, the festive season is a time to settle old scores, dispatch new enemies and indulge ... in murder.Here, ten masters of the genre serve up mystery and mayhem aplenty. From a dowager's missing diamonds to a Christmas party gone horribly wrong, these classic crime stories will delight, puzzle and satisfy long after the last strands of tinsel have been packed away.