John is a cash-strapped taxi driver in Dublin, who lives with his mother, Jean, who is drinking herself to death. He finds her comatose in her own vomit and drives her to the hospital where she recuperates until her next bout of drunkenness. John spends his time trying to get more work driving, hanging out with his one mate, arguing with his mother about alcohol, taxiing prostitutes, and palling with his younger brother, who has Down syndrome and lives in a home with other disabled kids. John rids his house of alcohol and tries to convince his mother to stop drinking but she screams at him and smashes the plates as he impassively videos her rampage.

After fearfully searching around town for his mother, he finds her drunk on the doorstep. Not knowing what else to do with her, he invites her to party with him and watches emotionless as she drinks and dances in the kitchen. She confides in him that when John's younger brother was born disabled, their father left, and she always saw the child as less than human, and nothing but a drain on her. But she says John was her precious child, who always came looking for her. After her husband left, she felt destined to be utterly alone the rest of her life, until she found alcohol.

John convinces her to enter a treatment centre, by screaming at her that she is breaking his heart and he can't take it anymore. He shows her the video of her raging for alcohol. The free centre can only keep her for one week, but the concerned director finds a place at a private clinic with a fee of 8,000 euros. Desperate, John calls his boss to ask for an advance, agreeing to do his bidding. John drives his mate Shane to the airport to leave the country, but on the way has arranged for him to have a cathartic meeting with his young son whom he almost never gets to see. Then John and Shane say a tearful goodbye at the airport.

John visits his mother at the new centre, along with his brother, and the mother makes an emotional connection with him. John's boss tells him to pick up something delicate for him. He drives to a desolate house where he finds a young Asian woman, abused and delirious in a bathtub. Disturbed and perplexed, he ends up driving her to the director of the treatment centre to get her help.

• Jack Reynor as John
• Toni Collette as Jean
• Will Poulter as Shane
• Michael Smiley as Jim
• Darine Ní Dhonnchadha as Bridie
• Gary Ó'Nualláin as Frank

Glassland was released theatrically in Ireland and the United Kingdom on 17 April 2015.

• Glassland at IMDb