Editing Mirror Story 3

We were approached by a merchant family in the Tiefling Confederacy, far in the south, at the coast. They were having massive shipping losses due to piracy; the pirates had the help of magic, and were causing a lot of damage. But it was complicated when we discovered that the sorcerous leader of the pirates was actually the disaffected middle son of the merchant family-- he knew he'd been cut out of the inheritance, and was using his knowledge of the family's shipping to guide the pirates, intending to, in effect, take his inheritance by force, and cripple the family that had cut him out.  

It ended in a climactic battle on a sinking pirate ship, inevitably.