In a first book from an Iowa-born author now living in Australia, three children discover a mysterious power and then must fight to keep it from evil hands. It begins as a game invented by the youngest, Lucy. She makes a manikin and invests it with the power of the Rellard by winning 12 trials--despite her withered arm. Her sister (Shelley) and brother (Georgie) are skeptical until the power banishes the insects at their summer cottage and cures Shelley's sunburn. Returning to school, each becomes so involved that the Rellard is forgotten--until they discover that their new friends, and Lucy's destructive teacher, are all in a conspiracy to steal the Power; but they are finally thwarted when Lucy manages to invoke the Power to save the town from a massive storm. Although lengthy, this promising debut has enough action and dramatic tension to keep readers interested. With so many magical props and menacing effects, the story's logic is not always clear; but the characters are three-dimensional and engaging.