You can only get into the Masoleum, which is due north from Hive: East, after talking to Norochj. He will give you the sign to activate the portal.

The guardian spirit greets you. Say you'll help, and he'll let you through. You'll have to kill quite a few skeletons, plus a giant skeleton, as you circle around. Search the ground for treasures. Eventually in the southwest corner you'll find the door to the inner chamber.

The inner chamber is just one room, with Strahan Runeshadow. He wants your blood ("the blood of an immortal") for a spell he's performing. Concentrate on killing him when the fighting starts - once he dies, everone else in the room instantly dies as well. You find his diary, which explains his twisted quest, as well as a skull in the floor.

When you come out, the spirit thanks you for your help and gives you 2000xp. That's it, return to Norochj to let him know the job is done.

Planescape Torment Walkthrough
Walkthrough Master Index