Tarzan and the Dark Heart of Time (Edgar Rice Burroughs Universe)

Tarzan, Lord of the Jungle, returns with a vengeance in this action-packed adventure by Philip José Farmer, Hugo Award winner, Nebula Grand Master, and author of the acclaimed Riverworld saga.
 
Tarzan’s beloved mate, Jane, has been kidnapped, and the furious ape-man will let nothing stand in the way of rescuing her—not even a sinister safari whose target is Tarzan himself. With fierce Masai trackers leading the chase, a trio of white hunters are hellbent on capturing the Jungle Lord. But as the pursuers, and their uncanny half-human tracker, close in from behind, Tarzan races toward even greater danger ahead.
For the trail leads to a bizarre, long-forgotten land boasting a multitude of strange and terrifying mysteries: the City Built by God, the Hideous Hunter, the One to Avoid, and most shocking of all, the Crystal Tree of Time—whose seductive powers could ultimately spell Tarzan’s doom…