Promise of the witch-king - R. A. Salvatore

Entreri and Jarlaxle find themselves in the Bloodstone Lands, caught between the ghost of a power-mad lich and the fury of an oath-bound knight

One of the long-lost books of the late Witch-King, Zhengyi, has been found. Its pages promise unimaginable powers-and the threat of death. But even the fact that the book kills anyone foolish enough to crack its cover does not stop people from fight over it . . .

Human assassin Artemis Entreri and his dark elf companion Jarlaxle have come to the demon-haunted wastelands of the frozen north at the request of their dragon patron. It doesn't take long for them to find themselves trapped in the middle of a struggle between powerful forces that would like nothing more than to see them both dead-or worse. But Entreri and Jarlaxle aren't just any wandering sellswords, and the ancient evils and bitter blood-feuds of the wild Bloodstone Lands may have finally met their match.

Promise of the Witch-King is the second book in the Sellswords trilogy and the fifteenth book in the Legend of Drizzt series.