 The book continues on from Avenger of Antares with Prescot being at home in his fortress in Valka with his wife and children.Attacked by four assassins in his own garden he defeats them and captures one but the latter is himself assassinated before he can talk.Employing the help of Evold Scavander, a wise man of Valka Prescot persuades the research into the contents of the two boxes in the flying boats which cause them to fly and makes some progress.