Mermaid to the Rescue (Purgatory Falls Mysteries, #3)

The last thing Brooke the mermaid needs right now is her mother showing up in Purgatory Falls to "help" her get organized to leave town. For one thing, she has a street fair to help with in a few days, and she's also just tripped over a headless man in an alley. She has murders to solve!
But she did make her family a promise that she would leave the paranormal town and return to the human world, so while she figures out if a series of murders might be the work of one serial killer, she weigh...