Kim works in a sewing factory making garments. This silent world is where she has been trapped for the past 25 years, ever since first arriving in Australia. One day, another worker brings a toy monkey into the factory. The monkey's appearance thrusts Kim back into her past as she re-lives the extraordinary plight by boat that lead to her arrival in Australia.

Along with her younger sister, an uncle and a fisherman, Kim flees her homeland by rickety fishing boat. Around her, the sewing machine tables, racks of fabric and spindles of cotton transform to become their boat of escape. As the boat leaves the ocean, the refugees struggle to face the realisation that they will never see their homeland again.

On the second day, a large oil freighter passes by but fails to stop. They are each trying to grapple with life out on the open seas when tragedy strikes. Pirates board the boat, smash their engine and attack both the men and Kim. In despair, Hanh does all she can to help her sister through the most terrifying ordeal of her life.

In the following days, food and water slowly runs out. Their arrival in Thailand is short-lived, and the four are force to face the reality that not all of them will make it through this journey. Mother Fish is based on the real-life stories of the 1.5 million refugees who fled Vietnam after the end of the war.