Atomfall's second expansion The Red Strain arrives Sept 16, 2025

Rebellion Developments announced on Friday that Atomfall will receive its second story expansion, The Red Strain, on September 16, 2025, bringing a new, tightly held location and additional mysteries to the studio's sandbox survival title. The developer released a short teaser trailer that outlines the basic setting and promises more information in the lead up to the launch.

Rebellion said the expansion centers on an industrial facility marked by unusual red foliage that may be linked to the titular "red strain." The teaser identifies the site as belonging to an organization called C.O.R.E. and shows automated robots guarding the compound, suggesting new environmental hazards and enemy types. In a description accompanying the trailer, the studio told players to "expect a highly confidential new location and plenty more mysteries to uncover." Rebellion did not announce a price, but confirmed the DLC will arrive on all platforms that host Atomfall, including PlayStation 5, PlayStation 4, Xbox Series X and S, Xbox One and PC, and will coincide with a title update containing gameplay adjustments and bug fixes.

The company has kept several key details under wraps. It is not yet clear...