The Coin

Unlocked by

 * Royal Secrets

Steps to Completing

 * 1) Talk to Esyllt at the Coffer Chasers Guild in Malina.
 * 2) Talk to Miller after defeating Muckrot Monark in Battle Quest Treasure Hunt.

Rewards

 * Cursed Boatswain Core
 * Queen's Magic Tool

Stories Unlocked

 * Empty-Handed