London in the late eighteenth century. The capital is thronged with French 'emigres and France's revolutionary Armies have swept across Europe and now face the English coast. A plan to land a French monarchist army in Brittany to relieve the pressure and to persuade Britain's ally Spain to remain in the ware is under way. In this atmposphere spies and rumours of spies are rife. One circle under suspicion is a group of astronomers who are searching for a missing star they believe to obrit somewhere between Mars and Jupiter. At the centre of this ring are brother and sister Guy and Auguste Montpellier. The star has been named Selene after Guy's dead amour, executed by the revolutionaries. A periodicaly deranged opium addict, Guy's decadence leads to him paying exorbitant sums for sex with prostitutes. All the prositutes share a remarkable resemblance to the dead Selene and all of them end up dead shortly after Guy's visit. Jonathan Absey is a government intelligence officer investigating spying rings. He knows that one of the group of astronomers is smuggling secrets on the Brittany landings to Paris, using his half-brother Alexander, a fellow astronomer, who has become besotted