The Enchanted Desert — Maureen Stephenson

Anna goes to Tangier to buy a rare coin, only to find that the seller, Mustapha, has gone to Tunisia. Alex Kennedy, the middle man, offers to take her there - but he is also the man who once jilted Anna. In Tunisia, Mustapha hands over the coin and then asks them to deliver a suitcase to his brother. Later, Anna is horrified to discover that they are transporting guns. But how is Alex involved, and who is the strange man who is following them?