Swords Against Wizardry

Description for SWORDS AGAINST WIZARDRY by Fritz Leiber:

THE FOURTH BOOK OF FAFHRD AND THE GRAY MOUSER

WHEREIN
a city thief and an expatriate barbarian venture to climb an unclimbable mountain and penetrate an unfathomable kingdom.

In the far northern wastes of Nehwon stands the unscalable mountain peak called Stardock. It is said that one may find demons and gods at its heights--not to mention fabulous treasure. Despite the harrowing danger, Fafhrd and the Gray Mouser are interested--especially when the Snow King's daughters make an appearance....

But even star jewels don't last forever. Soon the heroes must take on a new adventure, this time in the terror-filled kingdom of Quarmall, where sorcery and intrigue mix only too well, and the adventurers learn that often the end of a quest lies not in treasure, but in treachery, particularly when pitting SWORDS AGAINST WIZARDRY