The phone and the radio were dead, but they'd already heard the news: a mass murderer was on the loose. So goes the story in
Someone at the Door
from Richie Tankersley Cusick.
Hannah and her younger sister, Meg, were miles from the nearest neighbor, trapped in a raging blizzard, home alone. When two wounded, bleeding strangers show up, Hannah doesn't know whether to help them or turn them away.