What was supposed to be a relaxing summer turns into a fight for survival...

Kaelyn Fisher is spending her summer break before senior year with her grandparents in Cody, Wyoming. But a shooting at her doctor's office, followed by an explosion at the historic Irma Hotel, changes everything.

As the Star Brights begin taking over their once-peaceful town, Kaelyn and everyone she cares about find themselves in unimaginable danger.

With no safe place left, they make the difficult choice to leave their home and seek refuge with friends near Yellowstone Park.

But the sanctuary they're hoping for may be anything but safe.

Can Kaelyn and her grandparents escape the growing violence, or will leaving home be their fatal mistake?