#7: Shadows at Predator Reef – unabridged audio book on CD

Diving into deadly waters…
 The world's largest reef exhibit is coming to the Bayport Aquarium. Frank and Joe are stoked for the unveiling of Predator Reef, a three-hundred-thousand-gallon tank that houses small sharks, rays, and thousands of colorful fish. It’s also home to the aquarium’s new mascot, Captain Hook — a rare and valuable, five-hundred-pound, giant sea turtle.
 But instead of a big reveal, the boys get a big disappointment: Captain Hook has gone missing, along with loads of other exotic fish. Is the aquarium the target of a sinister smuggling ring? And can Frank and Joe do damage control before they’re trapped in a deadly underwater maze… with no way out?