"We are like secret friends..."
Dragged from New York to Texas by her newly divorced father, Scarlet Beldon braces for a lonely summer in a Victorian house that allows only the faintest of Wi-Fi signals. A stack of letters from a quiet, Irish violinist, introduces her to the house's former occupant, Clara Castle, who lives with a strict and paranoid father.
When a music box connects the girls' worlds, the sudden shift of the letters turns into reality as they take a dark turn. Given only a handful of hints, the girls must work together unlock the secrets of Clara's future and alter the course of her family's lives.