The Outlast Trials plays during the Cold War and breaks new ground for the series with the introduction of the cooperative game. The game is in active development at Red Barrel, and apart from its existence, the details are usually rare. What we know, according to Polygon, is that the game is not a sequel to previous games, and its co-op mode is designed for up to four players. From the official statement from Red Barrel we also know that the story is an experiment. Whether the game focuses on experiencing the experiment, getting rid of it, or both, is not yet known.
For more information about Outlast series, see our reviews of the original and its sequel praising their psychological horror elements.
[Source: Facebook, Polygon]