The Mystery of the Fifteen Sounds

"The Mystery of the Fifteen Sounds" by Van Powell is a children's adventure novel written in the late 1930s. The story centers on young Roger Brown, who aspires to be a "Modern Pioneer," inspired by his father’s expedition to Borneo. Throughout the novel, Roger collaborates with his cousin Grover, who runs a scientific research laboratory, to solve complex mysteries involving scientific principles, including the disappearance of dangerous inoculated rats and the mysterious "Voice of Doom." The opening of the story establishes a sense of urgency as Roger discovers that alarms have gone off in his cousin’s laboratory. He insists to Grover that something is awry, especially with the sudden quiet of the alarms. As they investigate, they find that the laboratory's white rats, carrying dangerous pathogens, have vanished. The plot unfolds with hints of mystery, danger, and adventure as Roger and Grover confront challenges that combine both science and intrigue, leading them into various thrilling scenarios while trying to uncover the truth behind the strange occurrences in the lab.