Mary escapes her warring aunts by sitting high in the tree that adorns their yard. Her younger brother, Nate, stands on the ground because he is afraid of heights. They communicate by can phone (two cans and a string). They are spending summer vacation with the aunts because their famous archeologist parents are in Turkey, looking for The Star of Midnight, an ancient and valuable sapphire. The children will have to endure the summer here. From Mary’s perch she can observe the entire neighborhood of St. George’s Lane. There are strange lights and sounds. Whose is the face in the window across the street? Why does the lady wheeling her crippled father down the street wear a heavy red coat in midsummer? What’s more, there is a panther loose from the zoo. What is happening here?