Milly Alcock and Toni Collette Trapped in Deadly Sauna in Upcoming Psychological Horror Film

In the coming years, Milly Alcock may be suiting up as the next Supergirl in the new DC Universe, but her next project is a far cry from the world of superheroes. The House of the Dragon breakout star is set to lead a psychological survival thriller called "Hot Mother," co-starring horror genre icon Toni Collette.

The film, the debut feature from Australian writer-director Lucy Knox, follows a mother and daughter who check into a remote wellness retreat, only to find themselves trapped inside a sauna with no way out and no one to hear them scream. What ensues is a tense, physically brutal fight for survival that blends psychological horror and raw endurance.

For Collette, the project marks a major return to the genre that has earned her a reputation as a "trauma horror icon" thanks to films like Hereditary and The Sixth Sense. Alcock, meanwhile, continues to expand her post-House of the Dragon resume, having recently appeared in Netflix's Sirens and with a high-profile DCU role on the horizon.

Hot Mother is being produced by Carver Films and Rapt Films, with backing from several Australian screen agencies. The film is expected to debut sometime in 2026, giving Alcock just enough time to trade her superhero cape for a towel and a bottle of water.