Act II, Ill Fortunes (the third day)

Veroth examines the stairwell and is confident there are no traps present.

You step onto the roof of the small tower and see that it has weathered the centuries better then the other buildings of the estate. Still, you can see that the floor is breaking apart in some areas. The central part of the level is taken by a 10-foot-square chimney of sorts. On either side, a mass of webs, attacked to the chimney and the 5-foot tall parapets which encircles the outer perimeter of the tower, and which block the way to the far side.

Durgrim does not detect any undead.

No, you only have some arrow slits on the ground level, some distance away form the ground, suggesting an elevated walkway inside. The top is encircled by a 5-foot high parapet hindering much of your view.

The party heads back down the spiral staricase, descending int the sublevel. Those outside will thus lose sight of the party.

The party descend the spiral staircase end end up in a dusty corridor. For those with Darkvision or who take the time to take out a source of light, they can see they're in a 10-foot wide corridor which is approximately 40-foot long and end in a sturdy wooden door. The wooden door looks old and in disrepair, but has faired better then the rest of the estate, probably on account of it being underground. Roughly 10-feet away from the stairs, there is a level resting on the norther wall. The lever is currently in the "up" position.

Veroth examines the lever and notice it is indeed connected to some mechanism, looking around, he notices some suspect markings on the northern wall, about 5 feet from the lever, further down the corridor. Whatever this level does seem to activate something over there. Veroth feels teh lever might be a bit broken and is not sure whether it will activate, or perhaps retract, whatever it is this lever is supposed to control...

Edit: Oh, and Durgrims's sight pick up no undead...

Edit 2: I decided to put a dotted circle around the area Veroth feels the lever will affect.