[She finds a small wooden chest with a letter written on what looks like paper made of seaweed attached to the lock. When Kay opens it with one of the keys from her hairpin, it reveals nothing except a metal headband with an intricate wave design embossed on it.]

Oh! My relatives were working on something that can allow humans to listen to siren songs without getting hypnotized...but that's the thing. It's still a work in progress.

Plus, we don't know yet if two magic artifacts can be worn at the same time.