The Mystery of the Fifteen Sounds

"The Mystery of the Fifteen Sounds" by Van Powell is a thrilling adventure tale of a boy named Roger Brown, who seeks to follow in his father's adventurous footsteps as a "Modern Pioneer." When unsettling events occur at his cousin Grover's research laboratory, Roger's bravery is put to the test. The alarms have strangely gone silent, raising Roger's suspicions about possible intruders or the malfunction of the whole lab. His instincts prove correct when they discover pathogen-carrying rats have disappeared. With a mystery to solve, Roger and Grover must work together, facing danger and using complex scientific principles to uncover the truth behind the lab's strange happenings.