Orphaned Roo Thorn feels like the unluckiest girl in the world. Until she discovers a letter. A letter which urges her to ‘Grab life by the wings and fly.'With the help of her aunt, Joni, Roo sets out to buy her dream horse – a fiery showjumper named Wonder Boy. Then Wonder vanishes without a trace. Determined to save him, Roo and Joni investigate his disappearance. But as the mystery deepens and more prize horses are stolen, the pair find themselves drawn into a thrilling – but dangerous – adventure . . . How far will they go, and what will they risk, to find Wonder?