Robin James has always trusted in logic and science—until the brutal murder of her younger brother shatters her reality. As she returns to her studies, hoping for normalcy, she instead meets with something far worse. Her best friend’s and roommate's eerie warnings, her disturbing experiences, and the sinister changes in the people around her all point to an unthinkable doppelgängers—dark, malevolent copies—are replacing those she loves. With the help of a kind professor and an unlikely ally, Robin must uncover the terrifying force behind the lookalikes before it’s too late. But as the body count rises and her own sanity wavers, she faces a chilling what if her double is already watching… and waiting?