Mystery: Sherlock Holmes.

Musing on the mysteries of the case, Watson dismisses the supernatural explanation but admits that his common sense offers no obvious solution. Where might a living and breathing hound hide by day, and who is the mysterious shadow out on the moor? Watson determines to find out what this man might know and whether he is the same person who provided the warning back in London. Meanwhile, Sir Henry argues with Barrymore over the chase …

…the most famous authors simply wrote because they needed to make money. Writers like Charles Dickens would write hundreds and hundreds of pages, and keep the story going by adding a cliffhanger at the end of every chapter. Similarly, Doyle only wrote Hound because of the public appeal for more Sherlock Holmes adventures, and because Doyle was experiencing financial problems. As a result, Hound is one of the longest Sherlock Holmes adventures he ever wrote.