After vanishing under mysterious circumstances from her home, a species of vampire known as mondlicht (German for Moonlight) named Marie Orleans finds herself in an enigmatic land in the shadow of a dark castle.

Armed with nothing but her sword, Marie decides to traverse the castle in order to find a way home. However, a vampire by the name of Carmilla rules over the land she will not give her secrets up without a fight. A fight Marie is more than happy to deliver.

With other time-displaced hunters and fellow vampires at her side, will Marie conquer the castle before sunrise?