Christmas morning, 1969. Eleven year old Esme Lonsdale is opening her stocking. Its contents are thoughtless and wrapped in a bizarre concoction of birthday paper and wet towels, yet Esme is filled with wonder that Father Christmas could have been so ingenious. In reality, Father Christmas is Diana, Esme's mother, a woman wracked with manic depression, an embarrassing ailment to which her husband, Colin, turns a blind eye. So when Diana goes missing in the snow, only Esme and a close family friend, the Duke of Cluny, are worried. But Diana is soon found in the stables, happily drunk and rescued from the blizzard by Jimmy, the irreverent stableboy. By Boxing Day morning, life changes forever for little Esme, when Colin discovers his wife in a passionate embrace with the Duke. And as the family are dragged home in a mess of tears and rage, it's clear that the affair is only the first skeleton to come tumbling out of the closet.