In an attempt to survive, a group of smart and ambitious astronauts, who go in a long mission to a distant planet, where they have a simulated mission, but there, incidents come to challenge them, as they spend about 500 days locked in their shop without any interaction with the outside world.
Nearly all the spooky bits are achieved by pure aural assault, and the characters are such stock types, haunted by such predictable backstories, it's like watching Solaris performed by sock puppets.
"400 Days" isn't strong stuff to begin with, but a few bewildering creative choices made by the production take a comfortably average thriller and reduces it to tone-deaf junk.