A young nun has a sexual awakening after her sister's death in Thunder. Elisabeth (Lilith Grasmug) is a 17-year-old nun on the verge of taking her vows when she is called home by the news that her sister Innocente (Léa Gigon) has died. Elizabeth learns that Innocente gained a reputation as a spawn of Satan due to her promiscuous behaviour with local boys Joseph (Mermoz Melchior), Emile (Benjamin Python), and Pierrot (Noah Watzlawick). However, after finding her sister's journal, Elisabeth begins to follow Innocente's belief that giving in to sexual desire can bring you closer to God.
Thunder is the feature film debut from Swiss writer/director Carmen Jaquier, inspired by Pier Paolo Pasolini's 1964 neorealist drama The Gospel According to St. Matthew. The film focuses on a teenage woman named Elisabeth, who spent the previous five years in a convent. However, she is called back home by her mother (Sabine Timoteo) and father (François Revaclier) to help on the farm following the death of Elisabeth's sister Innocente. However, Elizabeth finds a journal hidden in Innocente's clothes, which leads her down a similar journey of sexual awakening.
The plot of Thunder is somewhat reminiscent of last year's Benedetta, though in this case, the protagonist's spiritual and sexual awakening is less gratuitously depicted. However, Thunder does follow some predictable plot beats in its early 20th-century setting, where any expression of female sexuality is viewed as the work of the devil. While Thunder gets points for not being too exploitative with its subject matter, the film is ultimately not as interesting as the plot description sounds.