In the first book of this mystery series, Judy Bolton is resigned to spending several boring weeks at her grandparents' farm near Dry Brook Hollow. Her summer suddenly becomes interesting when she overhears some men talking about the Roulsville dam. Although, Judy does not understand the conversation, the men fear that she does and threaten her. Judy also becomes reacquainted with her childhood friend, Peter Dobbs, who gives her a cat that she names Blackberry, and meets the wealthy siblings, Arthur and Lois Farringdon-Pett. As the days pass, Judy learns that the Roulsville dam is cracked and...

The Bolton family moves into their new residence in Farringdon. Belonging once to an infamous family of thieves, the home is reputedly haunted by the ghost of the previous owner who was murdered in the house. It certainly appears haunted. Judy and Horace hear strange noises from the attic, and Horace vows to discover the source and unmask it at a ghost party. Meanwhile, Judy finds herself in the middle of a very difficult situation when she is forced to choose between two groups of new friends. Horace's ghost party provides the backdrop for a reconciliation of friends and the amazing...

Kay Vincent dances around singing the school song as Girls' Farringdon High burns to the ground. Kay's behavior is appalling to the other girls who are devastated about the loss of their school. Many girls, including Judy, have lost their posters which had already been submitted for an upcoming contest. The fire leads to several unsolved mysteries. Several people suspect Honey of starting the fire out of maliciousness, and while Judy cannot believe the accusations, she admits that she doesn't know Honey that well. Judy vows to exonerate Honey of all blame. The mystery deepens when Judy learns...

Judy regrets that she is leaving Farringdon for a vacation in the Thousand Islands just as life in Farringdon gets interesting. The police are on the trail of counterfeiters, but Judy won't be around to help them. Excitement does follow Judy, however, when she impulsively purchases seven Indian masks at an auction. Judy learns that the masks are rumored to be cursed and that misfortune befalls whomever owns the monster heads. At first Judy refuses to believe the nonsense, but after the young people arrive at camp, the heads begin to appear and disappear and change location within the storage...

Judy Bolton, Irene Lang, and the rest of their friends attend the presentation of a fortune teller at the Farringdon theater. Irene is called to the stage, and the fortune teller warns Irene not to go to New York to marry Dale Meredith. Irene becomes nervous and worried after her consultation with the fortune teller, and Judy fears that Irene will ruin her life based on the dire prediction. Judy knows that the fortune teller is tricking the audience in some fashion, but how can she prove that the fortune teller has some unscrupulous means of acquiring information? And how does the fortune...

Judy is surprised when Arthur Farringdon-Pett slips an engagement ring, a pigeon's blood ruby, on her finger. She forces Arthur to keep the engagement secret, as she still feels torn in her feelings between Arthur and Peter and needs more time to think. Meanwhile, Lorraine Lee guesses that Arthur has proposed to Judy. Lorraine decides to try to capture the thieves who robbed a fur store in Farringdon in an attempt to prove to Arthur that she can be just like Judy. When Lorraine disappears Judy and Arthur begin a desperate search for her, with no clue as to where she has gone. Judy and Arthur...

Judy and Peter work to expose and outsmart a group of real estate swindlers. The Piper family has won a piece of property in Roulsville which is 15 feet by 100 feet. Since the property is not wide enough for a house, Mrs. Piper must purchase the adjoining property at a much higher than usual price so that she can build a house. Peter is determined to help Mrs. Piper, so the young people design a home that can be built on a narrow lot of land and hire men to begin building the home. Soon after construction begins, the young people are warned to beware of the Red Circle. Strange sounds are...

When Judy and Peter become stranded in an abandoned house during a storm, the last thing they expect is to meet a ghost. The ghost turns out to be a girl named Sally who insists that she is being plagued by ghosts. While Judy and Peter hardly believe the girl, they do like her and want to help her. Judy takes her home, only to have her disappear during a party. Later, Judy and Peter learn that Sally's full name is Sally Vincent, of the crooked Vincent family. Sally is fortunately not like the rest of the family. She is to receive an inheritance in a will but the rest of the family is...

Judy Bolton is thrust into an intriguing mystery when a stranger rushes up to her and gives her a purse that is not hers. Unable to catch up with the stranger to return it, Judy searches the purse and finds a note written by someone named Blackie. The note has a picture of a gun and requests that the bearer meet Blackie after a certain lecture. After Peter contacts the FBI, an agent meets with Judy and Peter and confirms that Blackie is a wanted criminal. Judy and Peter feel that the criminal has mistaken Judy for someone else, but the agent contends that with Judy's red hair it isn't likely...

Judy wonders what has happened to Roberta's father, a sea captain, who writes letters to Roberta. It has been quite some time since Roberta received a letter from Captain Dunn. Roberta suddenly begins to remember snatches of her past-a garden with a stone lantern, flowers, her mother and father. When a strange man and woman show up at the Dobbs home asking about Roberta, Judy instantly dislikes them and wonders about their motive. They claim to be related to Roberta's father and claim that he has died in a shipwreck. After they leave, Judy tries to find Roberta but discovers that Roberta has...