In the winter of 1906, Lady Emily and husband Colin are invited to the opulent home of Baroness Ursula von Duchtel in the Bavarian alps. Outside is a mountainous winter wonderland with a view of Mad King Ludwig's fairy tale castle. Inside, the villa hosts a magnificent but eclectic art collection--as well as an equally eclectic collection of fellow guests, among them a musician, an art dealer, a coquette from the demi-monde, and Kaspar, the Baroness' boorish son-in-law, whom, it begins to appear, someone wants dead.

Almost forty years earlier, Niels, a young German lord, sings to himself in the forest surrounding those same alps, capturing the attention of a not-yet-mad King Ludwig. Niels and the king become fast friends, their relationship deepening into something more as their time together stretches on. But while King Ludwig is content to live out a fantasy where their responsibilities don't matter and the outside world doesn't affect them, Niels knows that their bliss cannot last forever...

Decades later, Emily continues to investigate Kaspar's increasingly lethal "mishaps" when tragedy strikes, ensnaring the guests in a web of fear and suspicion. It's up to Emily to sift through old secrets and motivations, some stretching far into the past, to unmask the killer.