Following his wife’s departure, "David" (Colin Farrell) is sent to a high-end hotel with a peculiar condition: he has forty-five days to form a genuine connection with someone or face transformation into an animal—specifically, a crustacean of his choosing, complete with its reproductive capabilities and extended lifespan—and release into the wild. He’s not the only guest in this strangely impersonal place overseen by a formal manager (Olivia Colman), quickly making acquaintances with a rather compliant man who walks with a limp (Ben Whishaw) and his confused companion who has a lisp (John C. Reilly). While "David" isn't exactly presenting himself at his best and may not be the ideal partner that he envisions, he does manage to connect with a woman who frequently experiences nosebleeds (Jessica Barden), and then with another who seems unable to see beyond her own face (Rachel Weisz), so perhaps he can avoid a future spent scuttling through frigid waters. Throughout his stay, it’s revealed that he has a secondary reason for being there, connected to his dog "Bob," which leads him to consider an escape plan. He then encounters a group of rebels who have rejected the hotel's relationship protocols, some having fled the almost military-like establishment, and now strictly prohibit any physical or emotional intimacy—even resorting to sewing their lips shut if they kiss. As he and his new partner (Weisz) attempt to adjust to this contrasting world, it’s unclear whether they are safer with these anarchists or would have been better off under the care of Miss Colman and her unusual staff. There's a certain captivating oddness to the narrative and the acting; as the story unfolds, we witness a man whose interest in romance—in any form—was at its lowest when we met him, gradually finding it consuming his life and threatening his survival. The supporting actors all provide strong, idiosyncratic, and mysterious performances, and the character portrayals—particularly from Weisz, Barden, and even Whishaw who isn't always known for expressive acting—contribute to a series of dystopian situations that are as detached in their handling of human relationships as they are bizarre and surreal in depicting how people cope with an oppressive social structure.

Source on TMDB