- An original, powerful tale following the trip of the young noble Amicia de Rune and her adorable yet smart brother Hugo
- Survive a great, enigmatic danger in a brutal, unforgiving world. With the Black Plague appeared deadly swarms of rats, indiscriminately devouring everything in their path.
- A seamless blend of adventure and stealth gameplay, deeply embedded in dark medieval mystery.
Set in 1348, Amicia de Rune is a young girl of noble descent who lives with her family in rural Aquitaine, which has been invaded by the English Army during the Hundred Years’ War. Her younger brother Hugo has been ill since birth, and their mother, Beatrice, an alchemist, has locked him away in the family estate for years while trying to devise a cure. While hunting with her father Robert in the forest, Amicia encounters signs of blight, and her dog Lion is gruesomely consumed by an unseen entity. They hurry back to the de Rune estate, but troops from the Inquisition led by Lord Nicholas arrive and raid the estate in search of Hugo, executing Robert and several servants. Beatrice helps them escape and instructs Amicia to take Hugo to his doctor Laurentius before she is killed.
Amicia and Hugo flee to a nearby village, where they learn that hordes of ravenous rats have been spreading Bubonic plague and devouring anything they come across. Evading hostile villagers who hold Hugo responsible for the plague and Inquisition soldiers, Amicia and Hugo reach Laurentius’s farm, only to find him bedridden by the plague. Laurentius implores Amicia to finish her mother’s work. When Laurentius’s house is overrun by rats, Amicia and Hugo flee with his apprentice Lucas to seek the hidden Château d’Ombrage. As they evade the rats and invading English soldiers, Lucas explains that Hugo’s blood carries a supernatural evil called the Prima Macula, which has lain dormant within certain noble bloodlines since the Plague of Justinian. Beatrice and Laurentius had been trying to find a cure, while the Grand Inquisitor, Vitalis Benevent, covets its power. They are assisted by the sibling thieves Melie and Arthur, but Arthur is captured before the remainder makes it to the Château d’Ombrage.
Lucas reveals that he needs a forbidden book called the Sanguinis Itinera to complete the elixir that may cure Hugo. Amicia infiltrates the nearby university to retrieve the Sanguinis Itinera while Melie heads off to rescue Arthur. Amicia recovers the book and rescues a young blacksmith named Rodric, who helps her escape. They reunite at the castle with Melie and Arthur, who reveals that he witnessed Beatrice in the Inquisition’s custody. Amicia insists they not tell Hugo, but Hugo overhears the conversation, and his condition abruptly deteriorates. Amicia and Lucas return to the de Rune estate, looking for answers in Beatrice’s research. In a hidden laboratory in nearby Roman ruins, they complete the elixir before returning to administer it to Hugo, relieving his symptoms. However, Hugo runs away and turns himself over to the Inquisition to find Beatrice, leaving Amicia riddled with guilt. Vitalis injects himself with Hugo’s blood so that he can possess the power of the Macula, but Lucas’s elixir delays its development. Hugo manages to escape custody and finds Beatrice, who reveals that the Macula gives him the power to control the rats. Beatrice and Hugo are recaptured, and Vitalis threatens Beatrice’s life in an attempt to force Hugo’s powers to fully awaken.
A month later, in January 1349, the Château d’Ombrage is attacked by a swarm of rats led by Lord Nicholas and Hugo, who is embittered against Amicia. Nicholas kills Arthur and orders Hugo to kill Amicia, but she reconciles with Hugo, and they work together to overwhelm Nicholas with the rats before he falls through the collapsing castle floor. The children then decide that with the power of the rats, they can take the fight to the Inquisition and rescue Beatrice. They head for the Bastion, a cathedral in which the Inquisition has set up its headquarters. Rodric sacrifices himself to allow the others to reach the cathedral where Vitalis is waiting, having bred thousands of rats that only he can control. Vitalis and Hugo use their Macula powers to send hordes of rats at each other until Amicia is able to kill Vitalis with her sling. Three days later, both the rats and the plague have disappeared, and life begins to return to normal, although many remain wary of Hugo and his power. Melie parts ways with the group, and Amicia, Hugo, Lucas, and an ailing Beatrice head towards the harbour to find a new home.