In "Third Warning - A Mystery Story for Girls" by Roy J. Snell, join Florence Huyler on a thrilling adventure on Lake Superior. As a fire threatens the picturesque Isle Royale, Florence and her cousin Dave, along with a loyal band of characters, must navigate dangerous waters and unravel mysteries to save the island's inhabitants. This classic mystery, replete with courageous acts, surprising encounters, and the spirit of friendship, will captivate readers of all ages.