What happens when Sherlock Holmes heads to Lovecraftian New England? What happens when Cthulhu makes an appearance in Victiorian Old England? This is a scenario that many authors have tried their hands at, possibly beginning with Neil Gamain's modern day classic A Study In Emerald, which one the Hugo Award in 2004 for Best Short Story. This story has been adapted to Board Games, a Graphic Novel, and more. It's available for free on Neil Gaiman's website, in a beautiful pdf, formatted to resemble a newsletter from 1914 (it even has fake advertisements).
In recent years, two trilogies from different authors have appeared, crossing over Holmes and Lovecraft, so there seems to be an increase in interest in such crossovers.
What follows is a detailed list of all known examples of Holmes/Lovecraft crossovers.
I warned you all that I like lists, so here's another one. As always, if you see something incorrect, or know of something missing, please let me know and I will do the appropriate research, and correct as necessary. hanwds at, possibly beginning with Neil Gamain's modern day classic
SHORT STORY ANTHOLOGIES
Shadows Over Baker Street (2003) by Michael Reaves and John Pelan (ed.)
"Sir 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 these and fourteen other dark tales of madness, horror, and deduction, a new and terrible game is afoot.
The terrifyingly surreal universe of horror master H. P. Lovecraft bleeds into the logical world of Sherlock Holmes, Sir Arthur Conan Doyle’s champion of rational deduction–in these brand-new stories by twenty of today’s top horror, mystery, fantasy, and science fiction writers, including:
• Steven-Elliot Altman • Elizabeth Bear • Poppy Z. Brite • Simon Clark • David Ferguson • Paul Finch • Neil Gaiman • Barbara Hambly • Caitlin R. Kiernan • Tim Lebbon • James Lowder • Richard A. Lupoff • F. Gwynplaine McIntyre • John Pelan • Steve Perry • Michael Reaves • Brian Stableford • John P. Vourlis • David Niall Wilson & Patricia Lee Macomber"
Shadows Over Baker Street is currently Out of Print, however, it is available on Kindle, as well as used copies available on Amazon.
Sherlock Holmes: Cthulhu Mythos Adventures (2015) by Ralph E. Vaughan
"Beyond Baker Street is a shadowy realm where cultists worship Earth’s past masters, the gods of the Cthulhu Mythos. Sherlock Holmes has seen beyond reality’s veneer and applied his keen analytical mind to the nightmare logic that drives ordinary men insane. When followers of evil try to free their monstrous masters, they find Sherlock Holmes ready to confront them."
Sherlock Holmes: Cthulhu Mythos Adventures is available in Paperback and Kindle
The Cthulhu Casebooks: Sherlock Holmes and the Shadwell Shadows (2016) by James Lovegrove
"It is the autumn of 1880, and Dr John Watson has just returned from Afghanistan. Badly injured and desperate to forget a nightmarish expedition that left him doubting his sanity, Watson is close to destitution when he meets the extraordinary Sherlock Holmes, who is investigating a series of deaths in the Shadwell district of London. Several bodies have been found, the victims appearing to have starved to death over the course of several weeks, and yet they were reported alive and well mere days before. Moreover, there are disturbing reports of creeping shadows that inspire dread in any who stray too close. Holmes deduces a connection between the deaths and a sinister drug lord who is seeking to expand his criminal empire. Yet both he and Watson are soon forced to accept that there are forces at work far more powerful than they could ever have imagined. Forces that can be summoned, if one is brave – or mad – enough to dare… "
Sherlock Holmes and the Shadwell Shadows is available in Hardcover, Paperback, and Kindle
The Cthulhu Casebooks: Sherlock Holmes and the Miskatonic Monstrosities (2017) by James Lovegrove
"It is the spring of 1895, and more than a decade of combating eldritch entities has cost Dr John Watson his beloved wife Mary, and nearly broken the health of Sherlock Holmes. Yet the companions do not hesitate when they are called to the infamous Bedlam lunatic asylum, where they find an inmate speaking in R'lyehian, the language of the Old Ones. Moreover, the man is horribly scarred and has no memory of who he is.
The detectives discover that the inmate was once a scientist, a student of Miskatonic University, and one of two survivors of a doomed voyage down the Miskatonic River to capture the semi-mythical shoggoth. Yet how has he ended up in London, without his wits? And when the man is taken from Bedlam by forces beyond normal mortal comprehension, it becomes clear that there is far more to the case than one disturbed Bostonian. It is only by learning what truly happened on that fateful New England voyage that Holmes and Watson will uncover the truth, and learn who is behind the Miskatonic monstrosity..."
Sherlock Holmes and the Miskatonic Monstrosties is available in Hardcover, Paperback, and Kindle
The Cthulhu Casebooks: Sherlock Holmes and the Sussex Sea-Devils (2018) by James Lovegrove
"It is the autumn of 1910, and for fifteen long years Sherlock Holmes and Dr John Watson have battled R'lluhloig, the Hidden Mind that was once Professor James Moriarty. Europe is creeping inexorably towards war, and a more cosmic conflict is nearing its zenith, as in a single night all the most eminent members of the Diogenes Club die horribly, seemingly by their own hands. Holmes suspects it is the handiwork of a German spy working for R'lluhloig, but his search for vengeance costs an old friend his life.
The companions retreat to Holmes's farm on the Sussex Downs, and it is not long before a client comes calling. Three young women have disappeared from the nearby town of Newford, and the locals have no doubt who is responsible. For legend has it that strange amphibious creatures dwell in a city on the seabed, coming ashore every few centuries to take fresh captives. As Holmes and Watson seek out the terrifying interlopers, the scene is set for the final battle that will bring them face to face with the Sussex Sea-Devils, and perhaps with Cthulhu himself..."
Sherlock Holmes and the Sussex Sea-Devils is available in Hardcover, and Kindle, with a pre-order currently for the Paperback.
Sherlock Holmes vs. Cthulhu: The Adventure of the Deadly Dimension (2017) by Lois H. Gresh
"FIRST in a new series of Sherlock Holmes thrillers!
A series of grisly murders rocks London. At each location, only a jumble of bones remains, along with a bizarre bone sphere covered in arcane symbols. The son of the latest victim seeks the help of Sherlock Holmes and Dr. John Watson, who discover a common thread that ties together the murders–and the persons responsible.
Bizarre geometries–based on ancient schematics–point to members of a secluded cult. These men and women build strange constructs that will enable other-worldly creatures to enter our dimension, seeking sustenance. As their power grows, even Moriarty fears that his empire is at risk—to the point that he seeks an unholy alliance with his eternal foe."
The Adventure of the Deadly Dimensions is available in Paperback, and Kindle.
Sherlock Holmes vs. Cthulhu: The Adventure of the Neural Psychoses (2018) by Lois H. Gresh
"SECOND BOOK in a new series of Sherlock Holmes thrillers!
Amelia Scarcliffe’s monstrous brood, harbingers of Cthulhu, will soon spawn. Her songs spell insanity, death…and illimitable wealth. And Moriarty will do anything to get his hands on gold, even if it means tearing down the walls between this world and a realm of horrors.
Meanwhile, after Sherlock Holmes’s last tangle with the Order of Dagon, horrifying monsters haunt the Thames, and madness stalks the streets of Whitechapel. Gang war between Moriarty’s thugs and the powerful cult can only bring more terror–unless Holmes and Dr. Watson can prevent it. But can they find the cause of the neural psychoses before Watson himself succumbs?"
The Adventure of the Neural Psychoses is available in Paperback, and Kindle
Sherlock Holmes vs. Cthulhu: The Adventure of the Innsmouth Mutations (2019) by Lois H. Gresh
"THIRD BOOK in a new series of Sherlock Holmes thrillers!
Both Fitzgerald and Moriarty travel to Innsmouth, the stronghold of the cult of the Old Ones. Holmes and Watson follow them across the ocean and discover a structure designed to enable the Old Ones to flood into our world and unleash horrors that — unless stopped — will annihilate all of humanity. Yet when it is destroyed people continue to mutate and go mad. Cthulhu rises over Devil Reef, ready to unleash his minions. In an epic battle — logic vs. brawn — Holmes must defeat Cthulhu and permanently seal the deadly dimensions."
The Adventure of the Innsmouth Mutations is available in Paperback, and Kindle
A Study In Emerald (2006) by Neil Gaiman
A wonderful reading of this modern classic by the author himself, Neil Gaiman.
"Alluding to both the Sherlock Holmes canon and the Old Ones of the Cthulhu Mythos, this Hugo Award-winning short story will delight fans of Sir Arthur Conan Doyle, H. P. Lovecraft, and of course, Neil Gaiman.
A Study in Emerald draws listeners in through carefully revealed details as a consulting detective and his narrator friend solve the mystery of a murdered German noble. But with its subtle allusions and surprise ending, this mystery hints that the real fun in solving this case lies in imagining all the details that Gaiman doesn't reveal, and challenges listeners to be detectives themselves."
A Study in Emerald Audiobook is available streaming from Amazon and Audible
Neil Gaiman’s A Study in Emerald (2018)
"This supernatural mystery set in the world of Sherlock Holmes and Lovecraft's Cthulhu Mythos features a brilliant detective and his partner as they try to solve a horrific murder.
The complex investigation takes the Baker Street investigators from the slums of Whitechapel all the way to the Queen's Palace as they attempt to find the answers to this bizarre murder of cosmic horror!
From the Hugo, Bram Stoker, Locus, World Fantasy, Nebula award-winning, and New York Times bestselling writer Neil Gaiman comes this graphic novel adaptation with art by Eisner award winning artist Rafael Albuquerque!"
A Study in Emerald Board Game (2013)
"A Study in Emerald is a game for two to five players based on the award-winning short story of the same name by Neil Gaiman. In this stylistic mash-up of Sherlock Holmes and H.P. Lovecraft, the worst has already happened and the world is now ruled by the Old Ones. However, a secret war is being fought to free mankind from their servitude. The game A Study in Emerald fleshes out this core idea by including historical figures from the late nineteenth century, most being persons involved in the anarchist movement of the time. Deck-building forms the core of the game. You use influence cubes to bid for the right to draft cards and take control of cities. Each player has a secret identity, either a Restorationist fighting against the creatures or a Loyalist attempting to defend the status quo. Which side you are on determines what you score points for. An additional twist is that the performance of other players on the same side as you can stop you from winning if they are doing particularly badly, so you really want to know who is on which side. More specifically, when the game ends – and this can result from multiple causes, such as a marker on the War or Revolution track hitting 15 or the assassination of a Restorationist player agent – then the sides compare their scores; which side has the lowest score automatically loses, then the player with the highest score on the remaining team wins the game."
A Study in Emerald was 2013 Meeples' Choice nominee, and a 2013 Golden Geek Best Thematic Board Game nominee.
A Study in Emerald Board Game is Out of Print, but may be located in the secondary market
A Study in Emerald (2nd Edition) (2015)
"It is 1882, and the old ones are already here. They arrived seven hundred years ago and have been ruling the Planet ever since. The majority of people just get on with their lives, accepting their monstrous rulers. However, a growing band of revolutionaries wish to free mankind from their slavery. These freedom fighters call themselves the restorationist. A secret war has already broken out between the restorationist and the forces loyal to the old ones. The invention of Dynamite has changed the balance of power, and a lone assassin now has the capacity to destroy an old one. In this shadow world of assassins, informers, police agents and anarchists, nobody is quite sure who is who and which side they fight for. This second edition of a study in emerald sports new artwork by Ian o'toole and Tatiana kuzilova along with a streamlined set of rules that will Hopefully help those folks who found the first version a Tad complicated. Inconsistencies have been removed and the number of available actions has been reduced to the minimum, whilst still retaining the mood of paranoia from the first edition."
A Study in Emerald Board Game (2nd Edition) is Out of Print, but may be located in the secondary market
Sherlock Holmes: The Awakened (2007)
"In the third case, the famous detective Sherlock Holmes and his trusted assistant, Dr. Watson, are investigating a mysterious kidnapping case.
Almost immediately, they are confronted by a formidable organization that worships a primal god, Cthulhu. This bloodthirsty sect seems to be ready to do anything in order to carry out its mysterious work against which only the great detective has the strength to fight.
It is up to you to uncover the threat that is menacing humankind; it is up to you to stop the activities of this organization!
A story which melds Holmes’ rationalism with H.P. Lovecraft’s supernaturalism, “The Awakened” leads you from the undergrounds of London to the isolated summits of Switzerland, from the sweltering bayou of New Orleans to the dense Scottish fog… Guaranteed thrills."
Sherlock Holmes: The Awakening is Out of Print, but available to purchase via Download
Sherlock Holmes: The Awakened - Remastered Edition (2008)
"The Sherlock Holmes series returns with this updated version of The Awakened, which brings a whole new dimension to the original title developed by Frogwares. Keeping with the traditional Point & Click gameplay style of the original adventure games, The Awakened has been totally rethought, offering players a new third-person view while keeping the original first-person view available also. The game puts the player into an investigation of the myth of Cthulhu - as imagined by author H.P. Lovecraft. Sherlock Holmes, assisted by the loyal Doctor Watson, investigates strange disappearances which seem related to the activity of a secret sect. The adventure begins in London, in the renowned Baker Street, taking us to investigate a disturbing psychiatric hospital near Bale, Switzerland, on to Louisiana and finally to Scotland. Key Features 2 points-of-view available at all times: new gameplay in 3rd person, giving a new dimension to the original game, or classic first- person point-of-view. An original confrontation between the universe of Sherlock Holmes and the myth of Cthulhu - a fight between the rational and the supernatural. Rich graphics, biting dialogue, disturbing characters and an excellent sound track create incredible turn of the century atmospheres. Play as the famous detective Sherlock Holmes and his loyal friend Doctor Watson. A new help system that shows the interactions available (objects and actions). Interact with more than 60 characters in 5 disturbing universes. Use and combine more than 50 objects, and discover hundreds of clues and documents to carry out the investigation to its final outcome."
Sherlock Holmes: The Awakened - Remastered is Out of Print, but currently on Steam