The Siren's Lament (5E)

From publisher blurb: A 5th Edition Mini-Dungeon for 4-5 PCs of Level 4 Sirens rarely find true love, but the one haunting this watery memorial managed the trick. Unfortunately her father, a powerful spirit called the Sea King, disapproved of the match. He conjured a storm to sink her lover’s ship, not realizing the depths of his daughter’s attachment. The siren’s suicide drove the Sea King build these winding passages in a fit of remorse. They are a monument to the love that he destroyed, and a home for his daughter’s anguished spirit.