While filming the dystopian indie drama “The Assessment,” stars Elizabeth Olsen and Alicia Vikander found nature to be a crucial touchpoint for understanding its strange, mesmerizing sci-fi world.

In theaters now, the debut feature by Fleur Fortuné is set in a post-apocalyptic landscape in which couples have to undergo a state-administered test to see if they can be allowed to become parents. Mia (Olsen) and Aaryan (Himesh Patel) accept an assessor named Virginia (Vikander) into their home to watch them for seven days. They soon find that the assessment literally requires the couple to demonstrate their parenting skills, as Virginia acts like an actual child that needs to be bathed and fed.

As the assessment unfolds, viewers also learn about the conditions that led to this society in which the government controls reproduction. Mia and Aaryan’s life is a mix of ultramodern and familiar elements — their house is located...