Silencing the Sisters

The sirens in this tideway have drawn countless ships to their doom. Wiping them out would be a boon to all seafaring folk. But you can't very well kill all of them. Only a fool would try that. The real dangerous ones are the elders. The "sisters" as they're known. Bigger, smarter, and stronger than the younger ones. Their voices carry far out to sea and bring in all the big "catches." I managed to track two of them to a den at the northern end of the tideway, but I can't take them alone.