Nocturne

The Stranger returns from his unknown previous mission. His superior assigned him a new mission, along with a dhampir named Svetlana. The mission is to infiltrate a small village in Germany, to recover a relic that can grant every vampire who possess it immunity to their vampiric weakness. In the village, the mayor tells them that a vampire Count has the relic in a castle outside the village. During their journey to the castle, they witness strange occurrences, such as vampires attacking and killing each other rather than working together. After arriving, Svetlana suddenly becomes hostile and attacks The Stranger, before escaping inside the castle. After the count's servant tips off The Stranger that the count has mind-controlled Svetlana in order to groom her, The Stranger enters the castle and kills the Count after battling his minions and brides, returning Svetlana to normal. The village mayor suddenly appears in front of them, revealing that he was the Count's father. After the latter usurped him to become the Count, he, along with his loyal servants, flee to the village. They kill its previous inhabitants before pretending to be them. For ages, he battles the Count in order to retake the castle but to no avail. This explains the fighting between the vampires. He thanks the Stranger for killing his traitorous son, and promises not to abuse the relic. The Stranger and Svetlana leave with the Count's bride to-be, who is not turned into vampire.

In the next mission, The Stranger is asked to investigate the small town where the dead come back to life and attack the townspeople. While on board a train, The Stranger is suddenly ambushed by a pack of werewolves who have a grudge against The Stranger for killing members of their pack in the past. After killing the werewolves, The Stranger jumps off the train before it explodes. After meeting with his contact and the town's reverend, The Stranger battles the zombies and saves any survivors he finds. One of the survivors says that the zombies came from the abandoned mine in the town. Descending into the mine, The Stranger discovers that insectoid-like monsters are the source of the zombie outbreak. With the help from his contact, The Stranger manages to seal off the mine to prevent them coming up to the surface.

On the third mission, The Stranger is asked to destroy the factory run by Al Capone's gang that secretly created an army of undead gangsters. After meeting with the informant, Icepick, (one of the reanimated mobsters that went rogue) The Stranger infiltrates a movie theater to get the proof of Capone's factory. There, he is confronted by Smiley, the gang's enforcer. With the help from Icepick, The Stranger manages to kill him. Entering the factory, he meets Smiley for the second time, and kills him again. After sabotaging the factory, The Stranger attempts to escape the factory. He finds Smiley blocking the exit. The Stranger kills Smiley for good by dropping him into a vat of acid.

In the final mission, The Stranger is asked to help Killian Hammond, Spookhouse's former operative. In France, Killian requests The Stranger clean the graveyard of zombies and demons. While investigating the graveyard, The Stranger concludes that it is Killian who summons them. When he goes to his mansion to confront him, Killian subdues The Stranger and locks him in his dungeon. As The Stranger tries to make his way out of the dungeon, Killian taunts him and reveals the reason why he is doing this; he was forced to retire from Spookhouse, because of his hatred and disapproval towards supernatural creatures who join the ranks of the organization, ever since a vampire killed his wife. The Stranger also meets Moloch, a demonic member of Spookhouse who was declared missing. After freeing him and helping him recover his strength, The Stranger and Moloch escape the dungeon and confront Killian, who begs The Stranger to save him. The Stranger ignores his pleas and silently leaves the mansion as Moloch exacts his revenge on Killian. While debriefing The Stranger, the Colonel apologizes to him for his ordeal and what Killian became. He advises The Stranger not to let his distaste of monsters get the best of him if he doesn't want to end up like Killian. To this, The Stranger agrees.

In Epilogue, The Stranger enters Spookhouse's headquarters only to discovers that all of its staff are gruesomely mutilated. Shocked and confused, The Stranger enters the briefing room where he reads a message on the wall, written in blood that said, "I finally found you, Stranger!" as the screen fades to black.

Nocturne is a survival horror adventure video game set in the late 1920s and early 1930s – the Prohibition and Great Depression era. The player takes the part of The Stranger an operative of a fictional American Government secret organization known as "Spookhouse", which was created by President Theodore Roosevelt to fight monsters. He investigates four strange cases and saves people from classic monsters such as werewolves, zombies, and vampires.