George is alone at Kirrin Cottage. The boys are in France and Anne is arriving soon for company.
George is thrown into a panic when Timmy cuts his neck and the vet makes him wear a huge cardboard collar. To avoid embarrassment for him, she packs her tent, a few supplies and disappears off to the moors to camp - alone! She leaves a note for Anne to join her when she arrives.
The girls set up camp near an old deserted cottage and are shocked to see mysterious lights and sounds coming from there at night. They also meet a very strange boy (with an
incredible split personality!) who is working on a archaeology dig nearby. The area is ripe with Roman remains.
They are delighted to be joined by the boys (who's trip to France had been cut short)
Once all together again, the Five set about solving the
mystery of the mysterious lights and sounds. With the help of the strange boy (and lack of it sometimes!) they discover a
secret trail leading to a find of Roman treasure. But, as usual,
danger is never far away...