You need to have a high enough repair skill.. just repair things around the manor and eventually it'll unlock for you. From memory it's light, hose, pool, that need fixing and then fix the binoculars...
After accepting the quest, enter the hallway and turn around, then click the big exclamation mark box at the top right of the screen. Head over to the kitchen in your room and click the big exclamation mark box. Go back to the main door in the hallway and click the big exclamation mark box to view a short scene