The third season of Apple TV+’s hit spy drama Slow Horses, which debuted on November 29, 2023, made a major change to a key character’s backstory. While the show is largely a faithful adaptation of Mick Herron’s Slough House novels, the television version of Sean Donovan underwent a significant transformation. This change has shifted the character’s entire motivation and moral complexity, creating a different kind of story for viewers compared to readers of the book Real Tigers.
From Accidental Killer to Grieving Avenger
In the source material, Sean Donovan is a man already burdened by a terrible tragedy. The book establishes that he was responsible for the death of his partner, Alison Dunn, in a drunk driving incident. This accidental killing shapes his entire character, filling him with a deep, self-inflicted guilt that drives his actions.
The TV show, however, completely rewrites this history. In Slow Horses Season 3, Donovan is portrayed as a man seeking justice for Alison’s murder, which was committed by someone else. He is not seeking redemption for his own crime, but rather revenge against the organization he believes killed her: MI5. This turns him into a more straightforward avenger, heartbroken over a loss he did not directly cause. Series creator Will Smith explained the creative decision, stating:
“It works in the book because you can go in his head… but on TV, you need to see that love and grief.”
The production team wanted to make Donovan’s motivation visual so the audience could feel his loss and understand the extreme lengths he goes to.
A Simplified Moral Dilemma
This fundamental change in backstory alters the core moral dilemma of the character. In Mick Herron’s novel, Donovan exists in a gray area; he is both a victim of circumstance and the person who unintentionally did something terrible. This “moral messiness” is a signature element of Herron’s writing, presenting a character who is hard to neatly categorize as good or evil.
The television version of Donovan loses this ambiguity. By removing his direct responsibility for Alison’s death, the show makes him a more sympathetic and less complicated figure. His actions are driven by a purer, more externalized anger rather than a complex mix of grief and self-loathing. While this may make him easier to understand, it also flattens the layers that made the book character so compelling.
A Changed Relationship with Catherine Standish
The alteration of Donovan’s past also had a major impact on his relationship with another central character, Catherine Standish. In the Real Tigers novel, Standish is not just a random hostage. She and Donovan share a complicated romantic history, which adds a deep layer of tension, regret, and betrayal to their interactions during the kidnapping.
On the show, that shared history is erased. The two meet for the first time at an Alcoholics Anonymous meeting that Donovan uses as a way to get close to her. Without their romantic past, their dynamic becomes one of growing sympathy rather than charged history. Standish comes to understand his pain and even assists him, but their connection lacks the complicated emotional baggage of the books, where their scenes carried the weight of a shared and painful past.
The Ripple Effect on the Story
This character change creates a ripple effect throughout the season’s narrative. Donovan’s quest in the show is primarily about exposing MI5’s corruption and the secrets within the Footprint file to avenge Alison. His journey is one of external conflict against the agency.
In contrast, the book’s Donovan is on a much more internal journey. His actions are as much about coping with his own unbearable guilt as they are about exposing the truth. This internal struggle is a key part of the novel’s emotional core, something that is necessarily softened for the screen adaptation. The show trades this personal tragedy for a more conventional revenge plot, which some fans feel makes the story less haunting.
The third season of Slow Horses is now streaming in its entirety on Apple TV+.
Also Read: Slow Horses Season 5 Episode 3: Release Time and Roddy Ho’s Dangerous Romance
