Eleven-year-old Danny's parents are storm chasers - which sounds fun and exciting, and it is, so long as you aren't the son who has to wait behind at home. And one night, after a particularly fierce storm, Danny's parents don't come back. Stranger still, the old sycamore tree in Danny's yard seems to have been struck by lightning, and when he picks up a fragment of wood from the tree's heart, he finds he can hear voices... including that of next door's rather uppity cat, Mitzy. The stick is a taro, a shard of lightning that bestows upon its bearer unnerving powers, including the ability to talk with plants and animals - and it is very valuable.

So valuable, in fact, that it attracts the attention of a Sammael, an ancient figure of darkness and a buyer of souls. And he will do anything to get his hands on it... And so begins a dangerous and daring quest. Danny, who is bewildered, alone and unaccustomed to acts of bravery, must confront his fears, find his parents and unravel the secrets of The Book of Storms...