Having escaped from the half-bombed, blackened power station where he was being imprisoned, 12-year-old Luke is finally reunited with his family above ground. But not everyone made it out of the power station, and the guilt over his friends left behind is eating Luke alive.With the help of ghost-girl named Alma and his friend Jess, Luke will have to face his past and confront his deepest fear, to try to save Ravi, the friend who was there for him in his darkest hours.A riveting, magical adventure set on the the waterways of a richly reimagined London.