In the haunting and sophisticated new thriller “Watcher,” Maika Monroe plays an American woman who is feeling uneasy in her new hometown of Bucharest. “Watcher” helps illuminate the hard-to-describe unease that women can feel by simply existing in the world. IFC acquired the film after it debuted to glowing reviews earlier this year at the Sundance Film Festival, and it’s currently playing in 750 theaters nationwide. “Watcher” is also the feature debut of an exciting new voice: Director Chloe Okuno, who rewrote the New York-based script to take place in Romania and reworked the character of Julia to make her truer to her own experiences as a woman.