For his sophomore feature, “A Piece of Sky,” director Michael Koch ventured deep into the Swiss Alps to unravel the threads of a remarkable story that had haunted him for years. A tale of love and violent passions, it had seemed almost impossible to accept at face value, until Koch found himself confronted by the power and majesty of nature in the remote, mountainous region. “In this landscape, you feel that there is something bigger that you cannot control,” he said.

Based on real-life events, “A Piece of Sky” is set in a remote Alpine village isolated from the outside world, where young love is put to the test. Anna comes from the village and has a daughter from an earlier relationship, while Marco is an outsider from the flatlands hired by the mountain farmers to work the rugged land. Together they experience the joy of new love and the closeness of family.

But when Marco suddenly starts losing control over his impulses and behaving erratically, a new tension rises in the community. Through the changing seasons and the harshness of life, Anna fights to preserve a love she believes can outshine even death.

Koch first encountered the improbable story that inspired “A Peace of Sky” on the radio years ago. It stayed with the Swiss native when he moved to Cologne, where he studied film and made his first feature, “Marija,” which had its world premiere in Locarno in 2016. Cutting his teeth in Cologne helped prepare him for a second film that would require the physically and psychologically demanding work of immersing himself in the forbidding landscape of the Alps. “I thought I had to be more experienced as a director to handle this project,” he said.

Koch spent months searching for the real-life Anna, ultimately finding her in a small mountain village and hearing her story firsthand. “I really had a feeling that it was her inner calmness, and her relation with nature, which I think allowed her to react differently to this illness of her husband than we might expect,” Koch said.

His encounter with her “was just the starting point.” The director began a period of intensive research, befriending countless villagers and delving deep into the region’s culture and traditions in order to write his script. “I try to be really precise and to find in this local environment the bigger [story],” he said. Koch also chose to cast non-professional actors from the region, ultimately spending three years laying the foundation that would allow him to gain their trust.

“With my first film, the approach was a documentary one,” Koch said Wednesday during an online presentation of upcoming projects by new Swiss voices, hosted by Swiss Films and the TorinoFilmLab. “It was also the case with ‘A Piece of Sky,’ with the difference that maybe I gave more space to what I found. All the stories, the places, the people I met during the research for ‘A Piece of Sky’ became really important. It’s something that’s really the backbone of the story.”

The villagers’ characters were shaped by the dramatic landscape around them. They lived hard lives in the constant presence of death, and Koch said their stories “made a great impression” on him.

“At the end, nature has so much more power than you, and you are so small. This experience was really important,” he said. “You also feel okay with it because you just feel that it’s not in your hands. Nature is so much stronger, and you are a little human being trying to do your best.”