Penumbra developer Frictional Games has decided to creep us out in the 18th century, and in an errie castle no less with Unknown.
The devs are using their HPL2 game engine, which they'll beef up to include creation tools for custom user content when the game releases in Q2, 2010.
"We have expanded the engine to include tools for testing, creating and editing levels," says the Swedish Frictional. "The tools are used during the production of the game and are also going to be part of the final release, allowing for end-user content creation."
See below for the first official teaser trailer for Unknown.