A young girl's passion for physics and engineering gives this book a platform from which to recruit girls (and boys) to the sciences. The story begins when Isabel Williams joins Class 2F at St. Leonard's School, but she seems so tiny and insignificant that no one takes much notice. In her first science lesson, however, she amazes everyone by insisting she knows more than fat Mr. Phillips, their teacher. Her uncanny knowledge and spooky behavior spell trouble at first--why so many secrets?--but when the class starts to study the life of great Victorian engineer Isambard Kingdom Brunel, Isabel seems to have a mysterious link to the 19th century world. Now engaged, her classmates have a bitter argument about Brunel's massive final creation--the steamship SS Great Eastern--and Isabel disappears. Only her loyal friend Robert knows where she might have gone.