Cosima lives at the Star Diamond Home for Children with her best friends Diya, Mary and Pearl. Since uncovering a dastardly plot and escaping their cruel captors, life has been one of peace and contentment. Alongside her friendships, Cos finally has a real family, too – and every day spent with her long-lost father is more magical than the last. But when a world-famous painting is stolen, Cos’s father is arrested for the crime. Cos and her friends know he has been framed – and they are sure that notorious thief, the Spectre, is responsible. Cos is determined that she won’t lose her father again – and the girls must use spirit, wit, bravery and ingenuity to solve the crime and bring him safely home…