WATCHER follows a married couple named Julia and Francis after they move into an apartment in Bucharest. Francis is comfortable in their new surroundings, but Julia struggles to feel at home. Her discomfort turns to paranoia when she starts to believe a man in a neighboring apartment watches her through the window. After Julia learns of a serial killer who decapitated a woman in their apartment complex, she’s convinced her stalker’s to blame. So, she decides to keep tabs on him instead of the other way around. Will Julia’s paranoia save her life or ruin her marriage and turn everyone into her enemy?