The unbridled scope of luxurious festivities organized in honor of the heiress to the throne of the Galactic Empire all pursues one goal: to veil an insidious conspiracy that has matured on distant planets. The Imperial Security Service was scrambling to find a time bomb planted in the path of the star princess. It is only by pure chance that Jules and Yvette d'Alembert manage to get on the trail of the attackers and discover that the "surprise" prepared by the conspirators is much more dangerous than any bomb.