Seeking refuge from a relentless blizzard, a bird-watching group takes shelter in a high school—only to find that the deadliest threat is already inside.

Kate Fox has her hands full when her sister Louise and her father's latest ex-girlfriend, Deenie, show up at her doorstep just as a freak snowstorm comes bearing down. But when the sheriff—snowbound and stranded out of town—calls on Kate to assist a van of bird-watchers stuck along the road, she has no idea what she's signed up for.

With the help of Deenie and Louise, Kate settles the stranded group in the local high school gym, hoping they can ride out the storm together. But as the blizzard howls and cell service dies, Kate and the eight quirky tourists find themselves utterly isolated. What began as a refuge quickly turns into a nightmare when, by dawn, one of the birders is found dead, murdered.

Trapped by the blizzard, Kate has to single-handedly preserve the crime scene and discreetly begin her investigation, all while keeping the ruffled birders calm. But she soon realizes that each of the bird-watchers has something to hide... and more than one of them had a reason to want the victim gone. Secrets run deep, and as the snow piles higher, so do the lies. With the murderer still among them and no chance of escape, Kate must untangle the deadly truths beneath the snow to avoid becoming prey to a killer in this flock.