Beatrice appears in the film transported alongside other students from Class 2 and Class 1 through a wormhole into another world. She arrives as part of the group consisting of Shalltear Bloodfallen, Aura Bella Fiora, Demiurge, Darkness, Subaru Natsuki, Puck, Viktoriya Ivanovna Serebryakov, and Filo. This group encounters the girl golem Pantagruel, who rescues them and leads them to a village for a reunion with Naofumi Iwatani's group.

Throughout the film, Beatrice participates in the collective efforts confronting the golem threat. She joins the group traveling to assist Tanya von Degurechaff's team after their location is identified. Later, she is among those returning to the village with Tanya's group following Pantagruel's revelation of an interdimensional travel device at a facility. During the climax, Beatrice contributes to the battle against the facility's guardian golems. She participates in the coordinated effort to launch Pantagruel toward the massive golem's left eye, enabling Kazuma Satou to later extract Pantagruel using his "Steal" ability.

Her established background as an artificial spirit created over 400 years ago by the Witch of Greed Echidna remains. Her role as Subaru Natsuki's contracted spirit, bound by a pact restricting her mana absorption solely to him, informs her participation in group activities and battles. Her mastery of Yin Magic, including spatial manipulation and offensive spells like Minya variants, aligns with her capabilities shown during the film's conflict sequences.

Her personality traits—initially aloof yet ultimately cooperative—are evident in her ensemble interactions. She maintains her distinctive speech pattern, ending sentences with "I suppose," and her dynamic with Subaru reflects their canonical relationship, emphasizing reliance and mutual support during the facility assault.