In the early 18th century, around 1708, England finds itself embroiled in a war against the French. At the center of this political turmoil is Queen Anne (Olivia Colman), a middle-aged monarch suffering from frailties and ill temper, who relies heavily on her childhood friend and trusted advisor, Sarah (Rachel Weisz). Sarah, a calculated and astute figure, aids Anne as she navigates the weighty decisions brought on by the ongoing conflict.
Into this intricate web steps Abigail (Emma Stone), Sarah's cousin, who arrives at the royal estate in a rather unfortunate manner—falling into muck as she steps out of her carriage. Upon her entrance, the castle's staff playfully mocks her, compelling Abigail to meet her cousin in a state that leaves much to be desired. With her family having fallen on hard times due to her father's misfortunes, Abigail desperately seeks employment, leading to her position as a maid in the castle. However, the other maids, displaying their mean-spirited nature, subject her to bullying and mistreat her, even causing her some injury in the process.
Meanwhile, Robert Harley (Nicholas Hoult), a local politician, is fervently campaigning for peace to end the war. In contrast, Sidney Godolphin (James Smith) argues vehemently for its continuation. Sarah skillfully sways Anne to tax the citizenry more heavily to fund the war efforts, drawing Harley's ire.
One night, as Anne suffers an excruciating gout attack, Abigail seizes the moment, stealing away into the woods to gather herbs for a makeshift remedy. It is here that she crosses paths with the dashing Samuel Masham (Joe Alwyn), setting the stage for a complicated romance. After sneaking into Anne's chamber to apply the herbs, Abigail's scheme is discovered by Sarah, who initially punishes her for the deception. However, when Abigail’s remedy proves effective in alleviating the queen’s pain, Sarah begrudgingly recognizes her potential and promotes her to assistant, granting Abigail more privileges and independence.
As time progresses, Abigail cunningly ingratiates herself with Anne, particularly through shared conversations about the queen's beloved rabbits, each representing a lost child. The bond strengthens until a shocking revelation comes to light when Sarah catches Abigail and Anne in a compromising situation. Enraged, Sarah confronts Abigail but ultimately, Abigail's influence grows, culminating in a scandalous request from Harley—asking Abigail to act as a spy within the queen’s inner circle.
Amidst political machinations, Sarah finds herself injured and incapacitated, throwing the balance of power into chaos. With Sarah absent, Anne is easily swayed by Abigail, who now basks in the privileges of her newfound position and her romance with Masham. As the war intensifies and personal betrayals surface, the stakes grow perilously high. Anne begins to feel the burden of leadership and the trauma of lost affection as Abigail spins her web of manipulation, fueled by a desire for status and love.
The final act delves into themes of loyalty, betrayal, and ambition, as the characters' fates intertwine in a shocking climax. As Anne’s health deteriorates, Abigail's role as a confidante shifts dangerously into one of control and treachery. In a twisted resolution, Abigail’s subservience is inverted, with her stepping on one of the queen’s cherished rabbits, symbolizing the complete unraveling of their twisted alliance and the harrowing consequences of ambition in the court.
