After the mysterious death of her older sister, Elisabeth (Lilith Grasmug), a 17-year-old girl about to take her vows, leaves her convent and returns to family's farm in a small village where she reconnects with her childhood friends, Emile (Benjamin Python), Pierrot (Noah Watzlawick) and Joseph (Mermoz Melchior).

      Set in 1900, the screenplay by writer/director Carmen Jaquier begins after the death of Elisabeth's sister, Innocente. The circumstances surrounding her death remain enigmatic initially, but that changes when Elisabeth discovers her diary which provides a small glimpse inside of Innocente's heart, mind and soul before her death. The film becomes increasingly darker and somewhat creepier without going over-the-top. So, Thunder avoids heavy-handedness throughout and remains, for the most, understated. To be fair, it bites off a little bit more than it could chew as it juggles the themes of faith, sex, love and friendship. It can be seen as a coming-of-age film, but an unconventional one that's often engrossing, but occasionally dull and tedious. Those are minor, systemic issues, though. Writer/director Carmen Jaquier has a great command of the film's melancholic tone and suspense as well as exposition. It seems like the plot could go bonkers or veer into horror at any minute, but it doesn't quite go there per se, although there are some elements of psychological horror. The flashbacks don't feel clunky or contrived. Elisabeth feels like a complex human being whose relationship with her older sister remains fascinating with a few surprises along the way.

      Lilith Grasmug gives a raw and emotionally convincing performance that feels organic. The real star of the film, though, is the landscape which turns into a character in itself. Like Carlos Reygadas and Terrence Malick, writer/director Carmen Jaquier uses nature as a form of poetry which, in turn, becomes part of the film's style and substance concurrently. The cinematography palpably captures the majestic quality of nature with images that speak louder than words. Poetry is often a form of protest for or against something, but Thunder---along with its poetic title---leaves that up to the audience's own interpretation, so kudos to Jaquier for trusting the audience's intelligence while avoiding preachiness. She also shows signs of restraint and her grasp of the concept that "less is more" by keeping the running time under 2 hours. At just 1 hour and 32 minutes, Thunder is a meditative, lyrical and quietly moving emotional journey. It would make for a good double feature with All Dirt Roads Taste of Salt.