Biggles and Ginger, are sent to Mexico by Air Commodore Raymond in an attempt to trace the whereabouts of a stash of diamonds that have been stolen by a London gang. They had been tipped off by David 'Tricky' Adamson, who had originally been involved with the gang but had fled to Canada after a murder had been committed in the diamond heist. He informed Raymond that the other three gang members, who rejoiced in the nicknames of 'Ritzy', 'Corny' and 'Nifty' had departed to Eltora in Mexico to keep out of the way of the authorities and to arrange a deal with an international dealer.