"The Moon-Spinners" is the tale of a young British girl on vacation on the Island of Crete with her aunt who is working on assignment for the BBC. When the two women arrive in a small coastal town to stay at the local inn, Sophia the innkeeper refuses to let the two stay at her inn. She says that there are no rooms available, because of a local wedding. Alexis, Sophia's son knows that there are plenty of rooms since the wedding is for a local couple. He persuades his mother to let the British women stay at the inn.
During the local wedding festivities at the inn the girl meets a young British man staying at the inn. He invites her and her aunt to have dinner with him during the wedding reception. On the next day after the local townspeople left the inn, the girl is invited to go swimming in the Bay of Dolphins by the young man. On the morning when she is supposed to meet him she learns from Sophia that he left for the capital on the last evening bus. Feeling disappointed the girl takes a walk down by the sea only to discover that the man she dined with the previous night was shot.
Clearly there were suspicious activities afoot on the island, since news of the robbery of a famous necklace was still circulating. By sheer chance the girl discovers that Alexis' uncle is the thief that stole the necklace and was planning to sell it to a wealthy woman sailing along the coast of Crete. Before long there was a fight on the woman's yacht, only to have the necklace break into three pieces. It was soon that the would be client to purchase the necklace discovers that it was stolen from one of her friends. At the end of the film Alexis' uncle Stratos was arrested for the theft of the necklace. The girl solved a mystery, and found love as well.