Tom Armstrong, commonly known by the common name of Captain Armstrong, could boast the amount of knowledge that he had or the discoveries he made. However, he is already 5 years retired. Armstrongs companion, named Harold Coventry, was a young man of about six-and-twenty years. Like his companion, the sea was his passion, and although he was not a very wealthy man, he managed to explore every sea. Old friends decided to get together again and go on adventures, but this time they are waiting for a very mysterious island.