The film begins with Alma in a close up speaking about Reynolds, and the relationship the two of them have. We then see Reynolds Woodcock as he prepares for the day by shaving, getting dressed and having breakfast with Cyril and Johanna, who is the woman he is currently in a relationship with. She cannot get through to him and Cyril soon after asks Johanna to leave. Reynolds then takes a trip to the country where at breakfast he meets Alma, who waits on him. He asks her to dinner and she accepts. He then takes her back to his cottage where he fits her for a dress and she in a matter of hours becomes his muse.
Alma moves into Woodcock's home where he also employs multiple women who put together the dresses he creates. Reynolds is a man who has a very specific routine, and doesn't allow anything to interrupt it as it all feeds into his ability to create beautiful dresses, which are works of art. While Alma becomes part of his creative life, she feels shut out by him in their personal relationship.
In an attempt to draw close to him, and feeling overlooked during Reynold's process of creating a wedding gown for the Princess, Alma sends all of the staff, including Cyril home for the evening in order to cook dinner and have a night alone with Reynolds. But, the evening backfires on her as he makes it clear she's signed up for this relationship, for him, the way he is and he isn't changing for her. The next day Alma puts poisonous mushrooms in Reynold's morning tea which causes him to nearly faint while looking over the Princess' wedding gown. He falls into and leaves it badly damaged. His team of seamstresses put it together and it is made new for the next day to be sent to her. Upon waking Reynolds is better, and he proposes to Alma after having seen a premonition of his late mother. The two get married.
Reynolds after a time becomes incapable of thinking and working with clarity, and he tells Cyril he wants Alma gone. But Cyril in all her coldness has grown to like Alma. Alma walks in on Reynolds saying these things, and we then see her at the cottage making a poisonous mushroom omelette for him, which he is suspicious of, but eats anyway.
We learn that Reynolds has found out about the poison Alma has been giving him, and it has become their way of getting through their marriage. When he spins out of control, she poisons him, making him vulnerable and completely reliant on her. And when he comes out of it, she tells him she wants him strong again and back to working with passion and clarity. This is what their life, their creation becomes.
