21 - Tom Swift and His Big Tunnel by Victor Appleton

n Tom Swift and His Big Tunnel, young inventor Tom Swift is called upon to tackle an engineering nightmare—a seemingly impenetrable mountain in Peru blocking a critical railroad project. With rival companies waiting for them to fail, Tom must develop a groundbreaking explosive to finish the tunnel in time. But the adventure doesn’t stop there. Alongside his loyal companions, he embarks on a perilous journey deep into the Andes, encountering lost cities, ancient secrets, and unexpected dangers. Can Tom’s genius outmatch nature’s toughest challenge? A thrilling mix of science, adventure, and mystery!