Geronimo Stilton returns to the Kingdom of Fantasy in the sixth book in the series, The Search for Treasure.
Summary of the Book
When Geronimo Stilton finds himself back in the Kingdom of Fantasy, he is shocked to say the least. Now he needs to fulfil the ?Ancient Gemstone Prophecy?. The Royal Sapphire has caught the eye of the evil empress of the witches. If she can unite it with the Royal Ruby, she?ll find immense power. If Geronimo Stilton doesn?t stop her in time, she?ll take over the entire kingdom!