Run the Gauntlet

Publisher's blurb: 13th of 20: The party is hired by a secretive ship captain for protection across dangerous waters. Soon afterward, a horrible storm wracks the ship, and the captain turns to what he claims is a safe haven. Unfortunately for the party, the captain is actually a pirate, and he and his fellow miscreants were ordered by the dark god Bane to compete for a mysterious treasure. Stranded and threatened to obey, the party must crawl into the island's deep dungeon and reach the prize before the pirates do.