For Companion hero Iris (Heretics Sophie Thatcher), the movie begins as a fairy-tale romance by way of rolling fruit: She and Josh (Jack Quaid) lock eyes in a grocery store produce aisle. He tries to be smooth, but fumbles and knocks over an entire display of oranges. They laugh together, and the rest is history; love at first sight. Its the start of something beautiful at least, until its not. Companion is about the point where things change in their relationship, a moment Thatcher tells Polygon she was setting up in her performance without even realizing it.[Ed. note: This post contains spoilers for Companions plot setup, and the first major twist of many.]In the broader story of Companion, the grocery store scene is pure fiction; Iris is a romance robot Josh has bought, and this meet-cute is one of a handful of standard fabricated introductions her manufacturers let clients choose from so their artificial partners can remember how they met.The reveal that Iris is a robot wont come until later, amid a cavalcade of violence that makes up Companions main plot. There are plenty of clues baked into the narrative: the way we see her wake up from a nap, cued by Joshs command. His nickname for her, Beep Boop. The knowing, sometimes revolted glances of his close friends. But if youre paying attention, you might notice Iris very distinctive walk a sort of mechanical glide. Even in her grocery store fantasy, where shes visualizing herself as human, she moves a little too smoothly to seem natural. According to Thatcher, this was not actually intended, though.I was just focused on my posture and walking slowly, but everyone was commenting on my walk seeming strange or off, Thatcher told Polygon ahead of the films premiere. She gets why her movement looks like that, though: Though she never went for any specific android walk, she did focus all on posture, which certainly translates to her staccato movement. Even within the trailer, theres that scene where Im opening the door and Im running out. I notice my posture and everything just feels off and strange but I think thats also just a part of me, Thatcher laughs.What she did focus on when building the character with Companion writer-director Drew Hancock was Iris natural charm, and how that would come out in telling ways like finding the eerie smoothness of her voice.I think theres a warmth and familiarity to her voice, Thatcher said. It calms Josh, in a sense. Its a little bit more quiet, its very feminine.For Thatcher, thats the best way to track Iris journey through Companion. My voice gets lower within the film as she turns up her intelligence. And that was interesting to play with, how the voice very slightly changes and she has maybe more rasp, or just a little bit more personality, Thatcher said. It becomes lower [when] she suddenly has control, and then in that monologue she has to Josh, where shes finally standing up for herself. Shes finally found her voice in every sense.The performance was rewarding for Thatcher, who (as the grocery store gliding might suggest) felt in tune with Iris journey on an intuitive level. Much of her transformation was from practical effects Thatcher wore contacts, changed her own voice, and had a real interactive display to slide around settings on during filming.But it helped that she also felt Iris burden of being so focused on Joshs needs. The experience helped her better understand some of her own experiences.Just playing into that femininity was interesting in the beginning, and made me feel restrained in ways as a woman too, Thatcher said. And I think that was the most empowering part of it all, because I find that a lot of the projects I do are strangely about control.It says a lot about the times were living in right now. She lacks control. Theres so many expectations thrown on you as a woman, but right now, specifically, as a woman [] its like you dont have control over your body. You dont have a say. But then she finally finds that.Companion is in theaters now.