Two mysterious women seek refuge in a run-down coastal resort. Clara (Gemma Arterton) meets lonely Noel (Daniel Mays), who provides shelter in his deserted guesthouse, Byzantium. Schoolgirl Eleanor "Ella" Webb (Saoirse Ronan) befriends Frank (Caleb Landry Jones) and tells him their lethal secret: They were born 200 years ago and survive on human blood. As knowledge of their secret spreads, their past catches up on them with deathly consequences.