It's the grand opening of Traps new superstore, but nothing is working. The lights won't turn on, the doors won't open, and the loudspeaker is broken. Geronimo must figure out who is trying to sabotage the grand opening.

All the mammoths have fled Old Mouse City! It's a total cat-astrophe! Not only because mammoths are valuable allies of the cavemice, but also because without them, the cavemice can't make mammoth milkshakes, their delicious national drink. Geronimo Stiltonoot must embark on a daring journey to find the mammoths...and avoid going extinct before he gets back!

"My sister Thea and my cousin Trap were not getting along! When Grandfather found them arguing over who would get to join me on a trip to Brazil, he forced us all to go together. My friend Isabela needed my help finding a mysterious emerald. Could Trap and Thea stop shouting their snouts off long enough to help find the stone?" -- Back cover.

The enchanted Winged Ring which Queen Blossom gave to Geronimo is missing, apparently stolen by the dark fairy Wither and her dark crow allies, and whoever possesses it gains enormous power and can travel between the Kingdom of Fantasy and the real world--now nightmares are starting to affect Mouse Island, the entire Kingdom is furious with Geronimo, and it is up to one mouse to set things straight and recover the ring.

Once again Geronimo Stilton is pulled into the Kingdom of Fantasy, where he is needed to fulfill the ancient Gemstone Prophecy, and prevent Scorcher, the evil Empress of Witches, from obtaining the Royal Sapphire which will give her immense power.

"Old Mouse City is in an uproar. The most precious artifact in the mouseum -- the Stone of Fire -- has been stolen! Geronimo Stiltonoot and his cavemouse friend Hercule Poirat are on the case. It's up to them to retrieve the stone from the ferocious Tiger Khan and his band of fearsome felines!"--Page 4 of cover.