

This episode begins with David explaining how gnomes make glass. Then he is called to the palace, where the king tells him about a little wizard named Tiraland. The wizard stole all of the gold in the castle, and now the trolls have thrown it into the eerie Black Lake. David has to ask permission to go to Black Lake from the ghost of Black Lake Castle. The ghost is a shape shifter, and agrees to let David go for only three days. David locates the gold with the help of an otter. The trolls have tied a rope around the gold bag and are about to pull it up. The otter removed the rope and ties it to a big rock. The trolls chase David and Swift, thinking they have the gold. Finally the trolls get scared by the ghost and give up the chase.
In the first episode ""Good Medicine"" we are told some facts that Gnomes, such as their height, weight, strength and what they like to eat. David also tells us all about their enemies, the Trolls.
Lisa is very worried about David and Swift, their red fox, when they don't arrive home from a trip in ""Witch Way Out"". In fact, they have been captured by some trolls called Hooley, Pat and Poopey. Lisa goes out to search for them and when she finds them, she has to set up a resuce mission. What can she do to save them?
David is called to Italy to treat a gnome girl. She had eaten a strawberry that had been sprayed with pesticide. The only plant that can cure her is the Shining Begonia. David travels to the Alps and outsmarts a snake to find the flower. On the way back, he meets Pot, one of the trolls.Pot challenges him to a dancing contest, and David cleverly keeps Pot waiting until the sun comes up. The troll turns into stone in the sunlight. David goes back to the palace and revives the gnome girl.