If you were offered a one-way trip to Mars, would you take it? That's what Mars One hopes to do, by sending crews of four people to Mars, starting in 2024. (They hope to fund the mission in part by making a reality TV show of the process.) Since the announcement of the program in 2013, more than 200,000 people have applied to go to Mars, permanently. In this somewhat moody documentary, we meet a few of those people, and get a sense of why they want to go—and what could make them stay.