Lake of Tears (Deltora Quest 1 #2)

Lief, Barda and their unruly new companion Jasmine are on a perilous
quest to find the seven gems stolen from the magic Belt of Deltora. The
golden topaz has already been found. But only when all the gems have
been restored to the Belt can their land be freed from the dark power of
the evil Shadow Lord. To find the second stone, the three heroes must
travel through territory ruled by the monster-sorceress Thaegan. Their
journey is filled with treachery, trickery and danger, and at its end
they must face the hideous guardian of the enchanted Lake of Tears.