A free-spirited young Iranian woman begins to explore a secret sexual relationship with her best friend, while her older brother finds new power inside their liberal, middle-class family by aligning himself with the thuggish morality police of the Islamic Revolution. Despite his own carefully concealed drug abuse, the brother takes it upon himself to install hidden security cameras inside the family’s home so he can monitor everyone’s activities, and his arranged marriage to his sister’s friend sets the two siblings on a collision course. Written and directed by Northwestern University alumnus Maryam Keshavarz, this impressive debut feature generates plenty of erotic heat, and Nikohl Boosheri, in her first screen role, gives a captivating performance as the sensually awakened heroine. But the movie is probably more notable for showing how the brother’s fundamentalism deforms the family dynamic, forcing the kind-hearted father to kowtow to his priggish son. Circumstance screens daily at Landmark’s Century Centre; a trailer follows the jump.