The party learned about Grell from the Svirfneblin priestess before setting out to clear the tunnel to the City of Glass Pools. On the first night, a half dozen Skum wandered into camp and were slain quickly. Another group of wandering monsters were easily dispatched the second night, and other than that there was no contact for the rest of the trip to the marked Grell area on the map.
The cavern came to a place where it split four ways, and two were covered in Razor Rock. Suji agreed to scout ahead in bat form to report back to the party. The first small cave to the left was empty. The one straight ahead, however, yielded the first Grell who was camped near the roof of the cavern, and fired a Lightning Lance at Suji. Suji attempted to lure it back to the party with no luck. After reporting as well as he could to the party, they all set off down the Razor Rock slowly, and engaged the Grell.
A long fight began with summoned monsters being called in to help bring the Grell down. The Grell was reinforced by three of its nest mates. After a long battle the party was victorious, and added the four Lightning Lances to its loot stores.