 At Cambridge University, the ape-like Horace Holly, nicknamed "Baboon", is visited by the dying Vincey who asks Holly to raise his only child Leo, and that he give Leo a chest on the latter's twenty fifth birthday.Holly agrees.It leads Leo, Horace and Job on an expedition to Ethiopia to find the lost "Pillars of Fire", said to grant immortality to whoever bathes in their light, and to be guarded by an immortal queen named Ayesha, called by her mistreated subjects "She Who Must Be Obeyed".