Serenity Submerged

Serenity Submerged by Craig A. Hart

A woman claiming to be an FBI agent appears on Shelby's doorstep and hands him a picture, asking if he recognizes the man in the photo. Shelby is shocked to see the face of a good friend staring back at him.  Little does Shelby know, the woman isn't the only predator on the prowl.
A group of hired killers has rolled into Serenity with one thing on
their minds: death. And it's up to Shelby to make sure the bullets fly
in the right direction.
Action drips in Serenity Submerged,
the fourth heart-pounding addition to the Shelby Alexander Thriller
Series. Relationships are questioned, secrets are revealed, and no one
is quite who they seem. Serenity will never be the same.