15 - Mansion of Mystery by Chester K. Steele

The chilling mystery begins when the prominent Langmore couple is found brutally murdered in their grand mansion. The prime suspect? Their own daughter, Margaret, who was present at the dreadful scene. Despite the mounting evidence against her, her fiancé Raymond Case staunchly refuses to accept her guilt, enlisting the services of renowned detective Adam Adams to unravel the truth. Penned by Edward Stratemeyer under the alias Chester K. Steele, this riveting tale will keep you on the edge of your seat.