"Elsa Park is a particle physicist at the top of her game, stationed at a neutrino observatory in the Antarctic, confident she's put enough distance between her ambitions and the family ghosts she's run from all her life. But it isn't long before her childhood imaginary friend - an achingly familiar, spectral woman in the snow - comes to claim her at last.Years ago, Elsa's now-catatonic mother had warned her that the women of their line were doomed...