The cave was an old shrine to Melora, and was filled with shifters and wolves. The humanoids wore tunics with the symbol of Bane on them, and graphiti praising him was defiling the walls.
When they reached the final room they discovered the robed figure that Tiales had glimpsed. He was definitely a werewolf, and after a hard battle the group emerged victorious.
They left the shrine and made it back to Sileen uneventfully.