This is the fourth book in the Lilly And Sarah Series . They are in their new town and the girls made a decision to volunteer at Memorial Children's Hospital . Lilly's parents get involved this time . Along their way they meet some awesome children as well as the Nurses & the Doctors who are helping the children with determination to help make them well again . Sarah keeps reminding Lilly that at the end of their journey visiting the children that she has a huge surprise for her . Just what will that surprise be ?