For cavemouse Geronimo Stiltonoot, life is one prehistoric problem after another! Geronimo's cousin Trap Stiltonoot is stung by a dangerous cavefly, which causes him to fall into an instant, deep sleep! To cure him, Geronimo and Thea must seek out the petals of the pink stinkrose, a rare and smelly flower. But it only grows on a very high peak! Can they make it there without going extinct on the way?