Ive played the beginning, I know there is a story to it.
You steal some orb
thus a "shadow" is trying to hunt you down
Alexander helps you to get rid of this "curse"
he brainwashes you torture many innocent people as a sort of ritual
you realize what you've done and make a potion so you forget everything
After this, you find a note from yourself telling you to kill Alexander
you travel through the castle yada yada yada
you meet Agrippa, a man who Alexander betrayed
you cut off his head (there's context to this, don't worry)
You find Alexander who's trying to summon a portal to his homeworld
you A. let him through. B. kill him. C. use Agrippa's head on the portal.
And that's pretty much a poorly written summary
(BTW it's not as scary as people say it is)