Trapped in a small Irish town, a self-absorbed, dysfunctional family aided by the town drunk must work together to defend themselves against an onslaught of creatures.

SYNOPSIS:

One year after losing his friend to an ominous entity, Kian Cassidy wanders through a celebrating crowd following a mysterious ceremony in the small town of Brimstone, Ireland; a bottle of whiskey clenched in one hand, a crumpled paper with his name in the other. He argues with his mother regarding his reputation as the town drunk and his inability to overcome his addiction. After the other residents leave town, Kian discovers the mayor rigged the ceremony, finding only his name in the drawing box. While he drinks in the local pub, a timid Alan Blake arrives with his narcissistic wife, Emily, and their three children: Jessica, Ronnie, and Anna. Kian attempts to send them away, but Emily insults him and demands they stay. Kian checks them into the hotel before racing from town. Jessica leaves the hotel to text her boyfriend as the clock strikes midnight; streetlamps going dark. She is rescued by Kian as she is confronted by a mysterious creature.

They quickly return to the hotel; Kian suggesting they move to the school basement. They duck into a nearby home to collect several firearms. The group is attacked by various creatures as they slowly move toward the school. Once they reach the basement, Kian reveals the town sacrifices one person each year to the creatures to protect humanity. If one of them does not sacrifice themselves, the Earth will be overrun. Emily attempts to secretly convince Alan to help her sacrifice Kian, but he refuses. They decide to move to a new location as more creatures gather in the school above them. Emily renders Kian unconscious; leaving him in the school as a sacrifice. Once the family discovers her actions, Jessica returns to rescue Kian. She is attacked by a creature during the rescue, but it hesitates to kill her. Kian and Jessica take refuge in a nearby home as Kian struggles to manage his alcoholism. Meanwhile, Emily is dragged into the forest by a group of small monsters. Alan finds her in a dilapidated home before they are chased by a tall, skinny creature. They are rescued by Jessica and Kian, but Kian threatens to kill Emily because of her deception. Alan shields Emily, but Emily steps forward; accepting responsibility for her actions. Kian chooses to spare her life before they regroup with the other kids at his home. Ronnie and Anna are attacked by a creature upstairs. The creature escapes; Anna clenched in its arms.

Alan quickly gathers weapons with the intent of chasing after his daughter. He argues with Emily and Jessica who assert they are going with him. Alan reveals to Emily that he knows about her affair: the reason he brought them on vacation. He recognizes he should have spoken with her directly rather than run from the problem. Emily feels remorse for her decisions and accepts responsibility for their situation; describing herself as the real monster. Jessica reveals she is pregnant, suspecting this is the reason the creatures cannot harm her. Kian chooses to help storm the church to rescue Anna. They discover that the creatures are actually people who have sacrificed themselves to the darkness year after year. The group rescues Anna as creatures pour into the chapel, but Emily unexpectedly chooses to stay behind. She sacrifices herself to save everyone else as the clock strikes midnight. A sobbing Alan embraces his children as the rising sun penetrates the broken windows.

BRIMSTONE