The adventure begins when the outrageous daredevil and super-sporty friend, Bruce Hyena, convinces Geronimo Stilton to join him on another extreme adventure: climbing to the top of Mount Kilimanjaro in Africa. Geronimo, who is not in shape for such a strenuous climb, reluctantly agrees, unable to say no to a friend.
The journey to the summit of Africa's highest peak is filled with numerous challenges and obstacles, including tricky terrain, unexpected hurdles, and the unique dangers of the mountain's harsh environment. Along the way, Geronimo and his friends encounter wild animals and face various fears, testing their limits.
The story is packed with humor, friendship, and educational tidbits, introducing readers to the geography, wildlife, and local culture of the region around Mount Kilimanjaro. Ultimately, the adventure highlights the importance of teamwork and perseverance.