The Trojan Horse
As Slough House struggles with its latest batch of MI5 rejects, they find themselves caught in a game of political subterfuge and espionage with global stakes.
Plot Outline:
1. The Setup:
A mid-level diplomat from the Chinese Embassy in London, Lu Qiang, unexpectedly defects, claiming to have sensitive information about a covert operation called The Trojan Horse. MI5 is skeptical of his motives and sends the case to Slough House to avoid risking their top-tier agents.
Jackson Lamb doesn’t buy Lu’s story either, dismissing it as another waste of time. However, when Catherine Standish begins investigating the diplomat’s background, she uncovers whispers about The Trojan Horse in old intelligence reports—an operation designed to infiltrate and destabilize Western cyber infrastructure.
2. The Stakes Rise:
Roddy Ho becomes obsessed with cracking Lu’s story and uncovers evidence of a massive data breach at the heart of the UK government. The breach links to a seemingly innocuous tech startup run by a former British intelligence officer. The deeper Roddy digs, the more he realizes this startup is a front for a multi-layered espionage operation—and The Trojan Horse is already active.
Meanwhile, River Cartwright stumbles upon a personal connection to the case: his grandfather David Cartwright was tangentially involved in the early days of the operation. This puts River in the crosshairs of MI5’s higher-ups, who want the case buried.
3. The Betrayal:
Slough House’s investigation turns deadly when one of their own is targeted. Louisa Guy uncovers a mole within MI5 working with the Chinese government, but before she can act, she’s framed for espionage. As the team scrambles to clear her name, Lamb manipulates old contacts and enemies, forcing MI5 to confront their failures.
4. The Twist:
The Trojan Horse is not just a cyber threat—it involves a high-profile double agent embedded in the UK government for decades. This agent’s betrayal could collapse the UK’s intelligence alliances. The revelation leaves Lamb uncharacteristically shaken, as he realizes the agent once worked under him at MI5.
5. The Finale:
In a chaotic showdown, Slough House uncovers the true nature of The Trojan Horse: it’s not just an operation—it’s a final move in a long game of espionage, designed to spark mistrust among the UK’s allies. The team races against time to expose the truth, navigating betrayals, bureaucracy, and their own personal demons.
The season ends on a bittersweet note, with Slough House saving the day but at great personal cost. Lamb hints that the worst is yet to come, leaving viewers eager for a potential Season 7.
This storyline combines the dark humor, character-driven drama, and intricate plotting that fans love, while adding timely themes like cyber warfare, betrayal, and geopolitical tension.
