Arriving in Venice,Jason is surprised to learn that he is the apparent author of a book entitled 'The Stones of Venice',which he assuredly is not. However,after he is attacked by two would-be assassins a jewel robbery takes place and Theresa Bonival,employee of a firm specializing in antique jewellery,is abducted - incidents closely related to events in the book and therefore sufficient for the police to ask for his help in their enquiries.
