Serpent Mage - Margaret Weis

After the four worlds Alfred has at last found
his people on Chelstra, the realm of sea. But his
travels have taught him to be cautious... and
Alfred soon realizes his caution is justified, even
among his own kind. The one person Alfred can trust
is, strangely, Haplo the Patryn. But Haplo's lord
has decreed all Sartan to be the enemy, and Haplo
dares not go against his lord. Now the companions
have arrived in a land where humans, elves, and
dwarves have learned to live in peace. Unaware of an
even greater threat to all the realms, it is
Sartan and Patryn who will disrupt this alliance of the
lesser races in their struggle to gain control of
all four worlds. Only Alfred and Haplo realize
that they have a much older -- and more powerful --
enemy than each other...