Here the complete walkthrough:
-pick up apple
-enter farm builiding
-pick up poison berries
-fight demon girl
-get poison berries
-use poison berries on apple
-go to old man
-give poisonous apple to old man
-go to old bum
-fight old bum
-get scrap of paper with password
-go to your flat
-pick up bloody knife
-go to police man
-give bloody knife to police man
-go to old woman
-buy hairy plasticine from old woman
-go to Black Metal woman
-buy keyprinter from Black Metal woman
-use your computer and enter the virtual reality world
-go to VR operator
-talk to her about Erik
-get the printed key
-go to suburban settlement
-pick up the old T-shirt
-go to mysterious red door
-open it with the printed key
-fight the Schrat
-get the Longsword
-go to the old hag
-buy "Tethra´s Lance" book from the old hag
-learn the skill "Tethra´s Lance" by reading the book in the inventory
-go to the Black Metal woman
-fight the Black Metal woman
-get the life jacket
-traverse the swamp with the life jacket
-go to the knight
-show the old T-Shirt to the knight
-fight the knight
-go to old hag
-fight the old hag
-get the oblation
-go to the totem
-use oblation on totem
-talk to Erik
-go to ruin of the building in Neurach
-talk to Erik
-fight the Lord
-the end