Troll Caves
This is a simple task for the PCs, though it will probably take them several strikes to polish off the Trolls (they should not return to the surface after every attack; with the Svirfneblin close by, they can rest safely in a nearby side-passage or side-cavern before returning to the fray). The trolls respond to decimation of their numbers by withdrawing into their "heartland" caverns (area 5 for the Topknots and area 10 for the Slaverers), placing guards at the entrance passages to their forwardmost cavern. At any given time, 25% of the Trolls in any particular location will be asleep (except at the guard posts at areas 1, 2, 6. and 7). If the PCs retreat from combat, the Trolls pursue them for d4+4 rounds, breaking off pursuit if they do not catch them in that time.
The caverns of the Trolls are filthy, unkempt, and reek of the body stench of their occupants. Gnawed bones (of everything the trolls have been able to get their claws and teeth on) litter the rocky, cluttered ground. The bones have teeth marks, and the marrow has generally been sucked out of them. Troll filth pollutes the caverns. Entering them should be extremely distressing for PCs with olfactory sensibilities.