Try Not to Breathe — David Bell

An ex-cop sets out to find her missing sister and discovers the shocking truth about her family...

A traumatic experience in the line of duty forces thirty-year-old Avery Rogers to abandon both her relationship and her position as a Kentucky State Police officer. She retreats to a college town where she works an unfulfilling job as a security guard, breaking up fights between drunken frat boys. 

But a frantic phone call turns Avery's life upside down. Her father -- a retired cop who never fails to convey his disappointment in Avery -- says her half sister is missing and in danger. Avery is sure Anna's just crashing with friends, but her father strong-arms her into searching for the sister she barely knows.

Anna Rogers is fed up with her family -- a half sister who resents her existence and a domineering father who thinks it's okay for cops to shoot unarmed civilians. She hits the road to attend a protest against police brutality, unaware of the danger that awaits her there. 

Just after catching a glimpse of Avery at the protest, Anna receives a shocking text. Now she's no longer road-tripping; she's running, pursued by an older sister she doesn't trust and a violent stranger who has been stalking her for weeks. 

When Avery discovers Anna's hiding place near a remote cave system, she risks everything to save her. Little do the sisters know that a secret is catching up to them -- a secret at the very heart of their family history.