Most nights, Angel dreams of avenging her mother and during her days, she hunts for her father. But her love for her younger sister, Abby (Tatum Marilyn Hall), hinders her desire for retribution. Abby is still in foster care and if Angel wants to assume legal guardianship, she needs to stay out of trouble. As Angel’s thoughts turn to revenge and its consequences, Abby pulls her back to normality with petty dramas, birthday presents and trips to the beach. The more they bicker, the more Angel delays her vigilante plans. Their relationship is as tender as a bruise.

The actress Jordana Spiro directed “Night Comes On” and wrote the script with Angelica Nwandu, a spoken-word poet and creator of the incisive gossip website The Shade Room. Ms. Nwandu is also a graduate of the foster care system. The result of their partnership is a film that balances penetrating clarity with compassion. Mirroring Angel’s dissociated gaze, Ms. Spiro’s camera sometimes wanders from her characters to fixate nakedly on families at rest or children at play. But when it comes to the sources of Angel’s pain, Ms. Spiro’s sharp-sighted scrutiny softens like eyes that have slipped — mercifully — out of focus.