Useless Bay by M J Beaufrand

There's a little boy missing and he usually went to the house next door to visit when he was bored.  But the quintuplets tell his family he's not there.  They do volunteer to help search for him.

Abrams sent me a copy of this book to read for review (thank you).  It has been published.

The quintuplets are giants to the little boy.  They're all over six foot tall.  They each have their skills and work well together.  But they are fearful of what might have happened to the boy.

Pixie notices something is attached to the buoy in the bay and she swims out to check it out.  She finds a body but it's not the boys.  It's his mother!  She swims around still searching for the boy (or his body) but what she finds is a deadly jellyfish and she goes into shock and starts swelling.  It's a good thing Frank always carries a first aid with him.

While she is on the beach flirting with death, the lady of the sea comes for the murdered women's soul.  She even has a mystic moment with Pixie but leaves her alive.

There's more death while they try to get to the bottom of the case.  Even the FBI gets involved.  The truth they are searching for isn't far away, but it looked benign until the monster came to life.

This story is set on Whidbey Island.  I've been there and with the fog and ocean sounds you really feel like there are ghosts and spirits about.  I find it easy to believe that Pixie might have been visited the lady of sea while lying at death's door.  The fact is that she should have been worried about the humans around her, not the ghosts.