When Silas Bird wakes in the dead of night, he watches powerlessly as three strangers take his father away. Silas is left shaken, scared and alone, except for the presence of his companion, Mittenwool - who happens to be a ghost. But then a mysterious pony shows up at his door, and Silas knows what he has to do. So begins a perilous journey to find his father - a journey that will connect him with his past, his future, and the unknowable world around him.