 When Sidney and Nigel are about to enter the site of a Bristol lecture, a surprisingly young author on the Celts approaches them to follow up immediately on a tip about a map to the "astronomicons", the lost keys to the druid cult in Stonehenge, hidden since the Romans conquered Britain. The soon learn it is an occasion to steal the map from the Gurul Nataz, it comes with an armed bomb and the youngster is no author but Andreas, the honest son of Sid s arch-enemy Fabrice De Viega -who survived, as they suspected. Junior assures them he hates his dad even more, being duped in a boarding school since his mother s death, but it turns out Fabrice risks everything to help them in order to save Andreas  life - but can even this bizarre alliance brave the ruthless crime syndicate?