Monsters in the game (A bit spoilerish?)

[MassacrMan]

I'm at the exact part, in the storage room.

The monster seems to just be circling the main cellar, and I'm not getting any saner sitting here in the dark.

Will he disappear, or do I need to find a way around him?

Sneak by him if you can, if he sees you. Just run, and keep running until you get back to the entry hall. I don't think they can follow you through those doors that require a load.