"The Wolf-Men: A Tale of Amazing Adventure in the Under-World" by Frank Powell is a novel written in the early 20th century. The story follows a group of explorers, including Professor James Mervyn and millionaire adventurer Silas K. Haverly, as they set out on an ambitious expedition to uncover the secrets of the North Pole using a newly constructed submarine. Their journey promises to be filled with extraordinary challenges and discoveries in a fantastical underworld inhabited by unknown creatures and perilous landscapes. The opening of the book introduces readers to the excitement surrounding the expedition's planning. Professor Mervyn shares his theory about a suitable submarine that can navigate the icy depths, convincing Sir William Seymour, another key character, to join in. As Haverly embarks on his trip, he encounters suspicious characters on a train, ultimately discovering a conspiracy to steal the submarine. The stakes rise quickly as he fights against time to warn his comrades before they can launch their polar adventure, setting the stage for an action-packed narrative filled with intrigue and unforeseen dangers. (This is an automatically generated summary.)