There's an old woman pacing outside the tower. When she sees you, she looks relieved. "You've come!" she exclaims as she approaches you. She explains the person you're looking for is here, locked at the top of this tower, and you must hurry. Before they drown.

The key is located somewhere in the ocean. She doesn't know where, but she knows who can tell you: the sea-witch who lives off the coast of Gallmarch. But you'll have to be prepared to give up something for this knowledge, because the sea-witch gives nothing away for free.