Unsettled by the bizarre death of her beloved Aunt Reba, Zoey Stone, amateur sleuth and teacher, searches for the mysterious cause. Her investigation leads her into the world of cutting-edge medical research where microscopic robots swim in bloodstreams. While her aunt's children struggle with homelessness, Zoey struggles to help them as she follows the evidence linked to Reba's death. She uncovers a chilling secret that leads to murder. Suddenly finding herself stalked, she must solve the puzzle of her aunt's death before she is abducted and before thousands of people are subjected to horrible deaths.