Tarzan on the Precipice (The Wild Adventures of Edgar Rice Burroughs)

Plunging into the Canadian wilderness to escape an overpowering grief, John Clayton, Lord Greystoke, divests himself of the veneer of civilization and again becomes the undisputed Lord of the Jungle, Tarzan of the Apes. But the North Woods is not the Dark Continent, and the ape-man swiftly runs a gauntlet of unexpected dangers. First, a vicious kidnap crew take him prisoner. Next, Tarzan encounters a band of Viking warriors who dwell in the vast crater of an ancient meteor strike, and makes common cause with a mysterious ape tribe who roamed the Americas long before man. Caught between warring worlds, his survival at stake, Tarzan stands upon a precipice of doom, both literally and psychologically. Will he triumph... or perish?