Stillhouse Lake: Stillhouse Lake, Book 1 by Rachel Caine

Gina Royal is the definition of average—a shy Midwestern housewife with a happy marriage and two adorable children. But when a car accident reveals her husband’s secret life as a serial killer, she must remake herself as Gwen Proctor—the ultimate warrior mom.

With her ex now in prison, Gwen has finally found refuge in a new home on remote Stillhouse Lake. Though still the target of stalkers and Internet trolls who think she had something to do with her husband’s crimes, Gwen dares to think her kids can finally grow up in peace.

But just when she’s starting to feel at ease in her new identity, a body turns up in the lake—and threatening letters start arriving from an all-too-familiar address. Gwen Proctor must keep friends close and enemies at bay to avoid being exposed—or watch her kids fall victim to a killer who takes pleasure in tormenting her. One thing is certain: she’s learned how to fight evil. And she’ll never stop.