This ebook contains links to a FREE AUDIOBOOK that can be downloaded directly to your device!<br /><br />First published in 1890, The Sign of Four is Sir Arthur Conan Doyle&#39;s second book starring legendary detective Sherlock Holmes. The story is complex, involving a secret between four ex-cons from India and a hidden treasure. More complex than the first Holmes novel, The Sign of Four also introduces the detective&#39;s drug habit and leaves breadcrumbs for the reader that lead toward the final resolution.