6) Search the bookcases to find the Book of Baxtorian. After reading the book, you will need to make your way to the Tree Gnome Village to get Glarial's pebble. The Tree Gnome Village is south of East Ardougne.
Strategy: Use Ardougne teleport to save time.
7) The Tree Gnome Village is surrounded by a maze. You need to make your way through this maze in order to reach the dungeon where Glarial's Pebble is located. The maze contains a number of monsters, but only low-leveled players should find them any trouble. The dungeon (marked by the usual exclamation mark on the minimap) is right next to the entrance to the Village itself.
8) Once you're in the tunnels, go east into the crate storeroom. Search the crates to find a Large Key (Picture). Head west past the hobgoblins to a gate, behind which is a Gnome, Golrie (Picture). If you try to open the gate without the key, Golrie will talk to to you and will give you a tip as to where the key is. Simply use the key on the gate to access the room. Talk to Golrie and he'll give you Glarial's pebble.
PART FOUR: THE WATERFALL
9) Head back to the Tourist Centre, stopping in East Ardougne to deposit your weapons and armour in the bank, including enchanted jewelry and runes. Food and potions are allowed.