You came across a stranded captain lamenting the loss of his crew. Meruna Sirens that dwell on the island lured the crew away under the power of their songs.
You found his crew in the Strand of Storms, but their minds were broken by the songs of the Meruna Sirens. You managed to put them all out of their misery and slay the creatures that lead them to this fate.
When you returned to the island, you told stranded captain what happened to his crew.