Whispers in the Mist (Black Winter, #3)

The mist is full of evil things―dark, twisted beings that think only of their own hunger―but Clare has clawed her way through. She and Dorran are alive against all odds, though relief is only temporary. Dorran is sick, and declining fast. The only way to save him lies in the mysterious Evandale Research Station, supposedly one of the few remaining places safe from the predators that lurk in the shadows. But the station is a three days' journey away, and it's unlikely their small group can endure that long out in the dark.

Because the danger they're facing comes not only from the ravenous hollow ones... but from each other.

This terrible new world has left scars, and the people left behind in it are nearly unrecognizable. As Clare fights to protect her ragtag family, she begins to realize a horrible truth: not everyone can be saved. And sometimes the worst monsters wear a human smile.