The Secret of the Island by Jules Verne

Following their escape from captivity, a group of castaways tries to survive on a remote island filled with strange events and hidden technology. As they explore, they uncover clues suggesting someone—or something—is watching over them. Gradually, they discover a secret connected to the legendary Captain Nemo and his submarine, the Nautilus. The story brings science fiction, survival, and mystery to a thrilling conclusion. It’s the final installment of a trilogy that ties together characters and legacies from earlier adventures.