The Cornwalls Vanish (previously published as The Cornwalls Are Gone‪)‬

When Captain Amy Cornwall's family goes missing, the Army Ranger will do whatever it takes to bring them home in this cinematic thriller that begins with a mysterious phone call and ends with a twist you'll never see coming.
In her career as an Army intelligence officer, Amy Cornwall has seen haunting sights half a world away. None compare to the chilling scene at her empty Virginia home.
A phone rings with a terrifying ultimatum: locate and liberate an unnamed captive in forty-eight hours, or her kidnapped husband and ten-year-old daughter are dead.
Now, in open defiance of Army Command, Amy must employ her most lethal tactics to save them. To succeed, she must discover not only who dispatched her on this mission, but why. Without her family, she's dead anyway.