New Ghosts, Old Tricks

Harper Harlow-Monroe has everything she's ever wanted. She has a husband she loves, a best friend who is only irritating fifty percent of the time, and a daughter who refuses to be "normal." So, basically, she has it all.
Then the unthinkable happens. During an afternoon picnic with her husband and daughter, Harper's yard is flooded with ghosts ... right as five bodies float by on the river. Harper's daughter Poe is finally in the thick of things because she's the only one who can communicate with the ghostly newcomers.
Worried, Harper calls in her friends Rowan, Maddie, and Ivy. Together, the foursome is going to figure out what's haunting Poe ... one way or another.
There's not much to be found regarding the victims. They were adventurers, making a name for themselves finding treasure at the bottoms of oceans and lakes. They were hired by a local billionaire, but nobody can figure out why and the man in question is being cagey.
Harper always knew her daughter would turn out gifted. The reality is different from the fantasy, however. Poe's magic is already strong, and when she gets a little encouragement from her friends, things begin to spiral.
It's an all-hands-on-deck situation for this battle, and only the strong will survive.