In Matt Osterman’s 2016 sci-fi mystery 400 Days, four aspiring astronauts embark on a simulated deep space travel mission that requires them to remain aboard a mock spacecraft underground for 400 days, but the 400 Days ending left the audience disoriented. The crew faces troubling situations one after the other until they are forced to leave the ship into a seemingly post-apocalyptic world. They are increasingly unable to determine what’s real and what’s not, and the true purpose of their mission eludes them. By the end of the film, audiences are left with more questions than answers.

As expected, the crew grapples with the psychosocial effects of their isolation. The crew members all suffer from personal issues, hallucinations, and hidden secrets from each other. On top of that, the ship's doctor seems to know more about the mission than she claims. Also, as expected, they must deal with unforeseen problems,...