For young Kariuki, life in a small village in central Kenya is one great adventure. And when he meets Nigel life becomes even more interesting. Nigel is from England and he has come to visit his great grandfather, the fearsome Bwana Ruin who owns the farm where all the villagers work. The villagers call Nigel the mzungu boy, and they view him with suspicion and fear.Nevertheless, Kariuki becomes friends with Nigel and the two spend happy days exploring the forest together. Then one day the two boys decide to hunt down Old Moses, the biggest, ugliest, oldest and meanest warthog in the forest. The hunt takes them deeper into the jungle than Kariuki has ever gone, and his beloved forest becomes a frightening place, filled with dangerous creatures, including the Mau-mau, the mysterious men who have guns and are plotting against Bwana Ruin and the white soldiers. And when Nigel suddenly disappears, Kariuki realizes that it is up to him to save his friend.