When her mother remarries after an all-too-short courtship, Lottie and her new stepsister must house sit for a night while their parents honeymoon in Reno. Lottie feels out of place at her new stepdad’s fancy ski cabin in Tahoe, especially with her new smart and sullen stepsister, Jade. And when a solar flare causes a massive blackout, Lottie knows they’ve got a long night ahead of them. Then, someone else shows up at the cabin—a cute, fast-talking stranger named Alex with his dog. Lottie's suspicions about him grow throughout the night, but when a fireplace malfunction causes a fire, the three of them are forced out into the blizzard and must rely on one another to find shelter and safety. Then, the wary trio encounters the perils of the wilderness as well as two mysterious young men who seem to know Alex. Now Lottie must decide who she should trust in order to survive...