George Barnard's life is turned upside down when she and her cousins embark on a treasure hunt. Soon they find themselves battling a merciless enemy who wants to change the world.

A cross-country thriller involving Quentin's invention of a state-of-the-art proto-computer dubbed 'the Algebra Engine'. With war on the horizon, the contraption is critical for the country's counter intelligence efforts and it's a race against time to prevent the machine falling into enemy hands.

As the summer comes to an end, George sets in motion a final adventure to protect a circus magician from an unscrupulous doctor who wishes to make use of his powers in the clinic.