Halfway through their year-long cross-country road trip, Ben, Charlie, and Olivia have crossed paths with a pair of mysterious strangers: Robbie, who has had disturbing visions of something looming on the horizon, and Danny, a young man desperate to finish his unfinished business. Now, the five have to end what the twins - and their peculiar Uncle Harry - started. As the road unfurls before them, they'll face monsters at Laundromats, ghostly loops, the (possible) reincarnation of Theodore Roosevelt, family secrets, an ominous man known only as October, the Winchester Mystery House, hungry shadows - and the demands of their own hearts. In the end, will Olivia and the Hawthornes thwart the destiny Robbie has foretold for them? Will they all reach their final destination together? Or will the sins of the past be repaid in blood?