Swan maiden Hilde sacrifices her magical wings to seek freedom in the human world, but when her pact with an upstart baron takes her the court of Ludwig II, she struggles to fit in, and only Jewish artist Franz, who has the power to paint souls, can help her escape her newfound prison.

When an encoded diary about Ludwig, the fairytale king of Bavaria who was declared insane and died mysteriously soon thereafter, falls into his hands, rare book dealer Steven Lukas is forced to go on the run as he becomes the target of Ludwig's deranged modern-day followers.