Emily Beecham stars as Alice Woodard, a careful and ambitious plant breeder working in a lab devoted to growing new flower strains. Her colleague, Kerry Fox Bella, is frustrated by a stubborn project: a hardy plant that can survive neglect, yet Alice and her team somehow unlock a variety that demands more care but delivers unexpected joy to those who nurture it. The mood in the lab shifts as the discovery promises a breakthrough that could redefine their work, and Alice pushes forward with a stubborn optimism, hoping to balance science with a touch of wonder.
Alice decides to name the experimental plants Little Joe in honor of her son, and she smuggles out a specimen for him to meet. Kit Connor plays Joe, a curious kid drawn to the promise of a flowering marvel that feels almost magical in its charm. The bond between mother and child grows quickly as the Little Joes begin to spread their presence, and Alice notes that these flowers seem to pollinate with unusual vigor, something she suspects might be tied to an unintended genetic quirk—perhaps a sterility in the plants that drives the rapid, aggressive pollination she observes.
The situation quickly spirals as the Little Joes unleash their unusual behavior in the lab. On the same day, Bella’s dog Bello vanishes, prompting Ben Whishaw to step in as Chris, a colleague who heads out to search for the missing pet. Chris’s encounter with the pollen becomes a turning point: he inhales the mysterious dust and later tries to kiss Alice, despite her evident reluctance, marking the first hints of a complicated tension between professional curiosity and personal boundaries. The pollen’s effect seems to echo through the people connected to the project, foreshadowing a broader threat to the team.
The next day brings a troubling discovery: Bella finds Bello, but the animal attacks her, and she insists that the dog has changed. Chris later confides in Alice that Bella’s mental health has been strained for years, including a past suicide attempt, and that she had Bello put down—changes that, he says, the plant could be amplifying. Alice grapples with the possibility that Bella’s fears might be grounded in reality, while Bella herself becomes a focal point of suspicion and concern within the group. In the tense atmosphere, a Lindsay Duncan as Psychotherapist is consulted to help untangle the growing paranoia and to examine the physiological oddities the pollen seems to trigger in living beings.
As the pollen continues to spread, Alice’s own son is accidentally pollinated and begins to exhibit strange, unsettling behavior. He starts sneaking his classmate Selma, played by Jessie Mae Alonzo as Selma, into the lab and even steals a Little Joe. He confesses that he is considering moving in with his father, Ivan, a figure connected to the community’s tense dynamics and played by Sebastian Hülk as Ivan. The film then tightens its focus on the fear of where the pollen could lead if left unchecked, with Alice’s mounting concerns about the plant’s potential to carry a harmful effect intensifying as she reviews test footage of subjects who have been exposed to its pollen. In every family that appears in the footage, relatives report that something about their behavior shifted after exposure, amplifying Alice’s sense of dread and responsibility.
But just as she begins to believe Bella’s earlier suspicions, Bella herself is exposed to the pollen and dismisses her earlier fears as paranoia rooted in her mental health struggles. The tension reaches a new height when Joe and Selma reveal that they stole the plant to pollinate Ivan, seemingly confirming Alice’s fears about a hidden virus-like effect carried by the Little Joe. Yet this turns out to be a misunderstanding, as Chris later reveals that the claim came from a miscommunication between him and Joe. The moment is a reminder of how easily fear can be weaponized in a small, high-stakes lab environment.
Following a confrontation with Chris, Bella claims she never inhaled the pollen and had simply been playing along to blend in with the others. The revelation is brutal and chaotic, culminating in a tragic accident where Bella falls down a staircase during a heated exchange with Chris. The incident becomes a turning point for Alice, who, despite growing evidence of danger, finds her crisis moment interrupted by the reality of a corporate decision to commercialize the Little Joe.
With the lab’s temperature being lowered in a last-ditch effort to suppress the plant’s effects, Alice contemplates drastic actions to destroy the Little Joes before they can be sold worldwide. Chris intervenes, trying to stop her by knocking her to the floor in a bid to shield her from the pollen, inadvertently exposing himself to the pollen in the process. The repercussions of this moment ripple through the lab and the company’s plans, underscoring the film’s tension between scientific ambition and ethical responsibility.
In the aftermath, the news reveals that the Little Joe has been nominated for an award, signaling that the plant will soon reach markets around the world. Chris offers a quiet, sincere apology for his earlier confrontation, and the moment gives Alice a reason to rethink her suspicions. She shares a quiet kiss with him, a small but meaningful gesture that hints at a new, uncertain happiness. In the film’s final act, she chooses to permit Joe to move in with his father while she embarks on a new life with her own Little Joe—an ending that suggests both renewal and the persistent lure of the plant’s beauty, even as its unsettling origins remain shrouded in questions.
