AN AUNT searches for her lost nephew—and dooms her sister.

A MOM gambles a miracle will cure—and not kill—her child.

A DOG finds his true purpose—when he disobeys.

Animal behaviorist September Day has lost everything—husband murdered, career in ruins, confidence shot—and returns home with her trained Maine Coon cat Macy to Texas to recover. She's forced out of hibernation when her nephew Steven and his autism service dog Shadow disappear in a freak blizzard. When her sister trusts a maverick researcher's promise to help Steven, September has 24 hours to rescue them from a devastating medical experiment impacting millions of children, a deadly secret others will kill to protect. As September races the clock, the body count swells. Shadow does his good-dog duty but can't protect his boy. Finally September and Shadow forge a stormy partnership to rescue the missing and stop the nightmare cure. But can they also find the lost parts of themselves?