Arthur Conan Doyle's Sherlock Holmes is among the most famous literary figures of all time. For more than a hundred years, his adventures have stood as imperishable monuments to the ability of human reason to penetrate every mystery, solve every puzzle, and punish every crime.

For nearly as long, the macabre tales of H. P. Lovecraft have haunted readers with their nightmarish glimpses into realms of cosmic chaos and undying evil. But what would happen if Conan Doyle's peerless detective and his allies were to find themselves faced with mysteries whose solutions lay not only beyond the grasp of logic, but of sanity itself?

In this collection of all-new, all-original tales, twenty of today's most cutting-edge writers provide their answers to that burning question.

"A Study in Emerald" by Neil Gaiman: A gruesome murder exposes a plot against the Crown, a seditious conspiracy so cunningly wrought that only one man in all London could have planned it--and only one man can hope to stop it.

"A Case of Royal Blood" by Steven-Elliot Altman: Sherlock Holmes and H. G. Wells join forces to protect a princess stalked by a ghost--or perhaps something far worse than a ghost.

"Art in the Blood" by Brian Stableford: One man's horrific affliction leads Sherlock Holmes to an ancient curse that threatens to awaken the crawling chaos slumbering in the blood of all humankind.

"The Curious Case of Miss Violet Stone" by Poppy Z. Brite and David Ferguson: A girl who has not eaten in more than three years teaches Holmes and Watson that sometimes the impossible cannot be eliminated.

"The Horror of the Many Faces" by Tim Lebbon: Dr. Watson witnesses a maniacal murder in London--and recognizes the villain as none other than his friend, Mr. Sherlock Holmes.

With thirteen other dark tales of madness, horror, and deduction, a new and terrible game is afoot:

"Tiger! Tiger!" by Elizabeth Bear
"The Case of the Wavy Black Dagger" by Steve Perry
"The Weeping Masks" by James Lowder
"The Adventure of the Antiquarian's Niece" by Barbara Hambly
"The Mystery of the Worm" by John Pelan
"The Mystery of the Hanged Man's Puzzle" by Paul Finch
"The Adventure of the Arab's Manuscript" by Michael Reaves
"The Drowned Geologist" by Caitlín R. Kiernan
"A Case of Insomnia" by John P. Vourlis
"The Adventure of the Voorish Sign" by Richard A. Lupoff
"The Adventure of Exham Priory" by F. Gwynplaine MacIntyre
"Death Did Not Become Him" by David Niall Wilson and Patricia Lee Macomber
"Nightmare in Wax" by Simon Clark