Robert Merivel, Robert Downey Jr is a bright, impulsive young doctor who secures a place at the court of King Charles II after saving the King’s beloved spaniel. He basks in the glow of court life, enjoying flirtations, witty company, and a grant of influence that comes with being a royal favorite. The King soon imposes a pragmatic marriage arrangement: Merivel must wed Celia, Meg Ryan the royal mistress who has fallen from favor, a ruse designed to fool the King’s own mistress, Barbara Castlemaine, Polly Walker. Merivel accepts, seduced by the proximity to power, while Celia is installed in a house in Kew and the King can visit in secret.
Bidnold, an estate in Suffolk, becomes Merivel’s new home, and with the steady guidance of Will Gates, Ian McKellen the capable estate manager, he begins a life of surface splendor and quiet restoration. The estate hums with activity as Merivel tries to balance indulgent pleasures with a growing sense that something essential is missing. Yet the fragile equilibrium shatters when Merivel breaks the King’s cardinal rule: he dares to fall in love with Celia. The revelation launches a chain of events that tests his loyalty, his craft, and his conscience. To document Celia’s beauty, the King commissions Elias Finn, David Thewlis, a cunning artist who uses the portrait session to uncover Merivel’s true feelings. When Elias tricks Merivel into admitting his romance, Celia’s heart remains out of reach, and Merivel is banished from court, sent back to life as a physician with a heavier burden to bear.
Driven to redemption, Merivel reconnects with his old friend John Pearce, Hugh Grant, who now runs a Quaker sanitarium. There he meets Katharine, Mary MacLeod, a troubled woman whose husband abandoned her after their daughter’s drowning. The two become lovers, and when Pearce falls victim to consumption, Merivel tends his dying friend and learns that Katharine is pregnant with Merivel’s child. After Pearce’s death, Merivel and Katharine choose to depart together, seeking a new life away from the courtly intrigues that defined his earlier years.
Their path leads back to London just as the Great Plague grips the city. Katharine gives birth to a daughter, Margaret, by Caesarean section, but she dies from the procedure. Merivel pledges to care for Margaret, a vow that will anchor his future. In the plague’s crucible, Merivel returns to the healer’s duty with renewed purpose. He tends the sick, separates the afflicted from the healthy, and eases the dying—yet to protect his own identity, he assumes the alias “Pearce,” a tribute to his late friend, John Pearce.
The King, impressed by the man he sees finally becoming, calls on Merivel to help Celia and the plague victims. Merivel’s compassion and skill reaffirm his worth, and when asked his name during these perilous times, he answers as Pearce, continuing to protect the truth of who he is. A catastrophe soon follows: London is engulfed in fire, and Merivel races to save his infant daughter, only to vanish into the blaze and drift away, unconscious, on a river about to swallow the city’s end.
He awakens back at Bidnold, cared for by Will Gates, and begins to reconstruct a life defined by purpose rather than pleasure. As Merivel heals, a nurse arrives at Bidnold bearing Margaret, alive and well, confirming that the King’s faith in him has not been misplaced. The King restores Bidnold to Merivel, vowing it will never be taken away, recognizing the depth of the man he has become. The film closes with Merivel returning to London, Margaret in his arms, ready to establish a new hospital with the King’s support, a testament to transformation, mercy, and the enduring power of care in the most perilous of times.
