Like most mothers, Catherine would slip into her sleeping newborn's room, listening to make sure her baby was still breathing—still alive. Now her daughter is eighteen; however, Catherine continues to check on her at night. She can't help herself—the intrusive thoughts rise up again and again and anxiety grips her, keeping her awake. Soon Anya is leaving for university, but any excitement Catherine might feel for her daughter is drowned out by terror. Cleaning out her late mother's dusty, decrepit house, visiting her mentally deteriorating father at his care home, and supporting a bereaved woman at work only stirs up more emotional stress. Soon, her behavior is out of control. But while Catherine obsesses, she does not see the dangers in front of her—and both mother and daughter will be forced to deal with the painful truths that are keeping them trapped.