Wanderers - Chuck Wendig

The story is an epic tapestry of humanity, told in a chorus of disparate voices, including Shana, a young girl who wakes up one morning to discover her sister in the grip of a strange malady. She appears to be sleepwalking. She cannot talk and cannot be woken up. And she is heading with inexorable determination to a destination that only she knows. But Shana and are sister are not alone. Soon they are joined by a flock of sleepwalkers from across America, on the same mysterious journey. And like Shana, there are other "shepherds" who follow the flock to protect their friends and family on the long dark road ahead. For on their journey, they will discover an America convulsed with terror and violence, where this apocalyptic epidemic proves less dangerous than the fear of it.