It’s hard to accept that Slow Horses is only one episode away from closing another explosive season — and, as always, it took just six episodes to get there. Episode 5, “Circus,” delivers a storm of twists, betrayals, and uneasy alliances as the pieces of the destabilization plot finally lock into place.

After the accidental death of Dennis Gimball, the Libyan rebels behind the operation keep advancing their mission with chilling precision. MI5 scrambles to understand the scale of the threat, but Jackson Lamb (Gary Oldman) already knows what’s happening: the enemy is replicating the British government’s own old-school destabilization tactics. The next phase is clear — “blind the enemy.”

Whelan’s arrogance and Diana’s breaking point

Inside MI5 headquarters, Claude Whelan celebrates his rival’s “accidental” death, proving once again how unfit he is to lead British intelligence. Diana Taverner (Kristin Scott Thomas), barely holding her temper, keeps her focus on the bigger picture. Yet Whelan, drunk on false confidence, insists on taking control — and his incompetence only deepens the disaster.

Meanwhile, Tara Younis (Aimee-Ffion Edwards), Roddy Ho’s mysterious girlfriend, is arrested under suspicion of collaborating with the terrorist cell. During her interrogation by Emma Flyte, she claims she was coerced after getting involved in Libyan protests and insists she only played along to survive. Even the ever-skeptical Diana believes her, ignoring Lamb’s warnings that something is off.

The trap within the trap

Tara provides a code she says was used to breach MI5’s database through Roddy’s computer — a key, she argues, to trace the source of the attack. While Flyte tests the code, Claude organizes an undercover operation: Tara, now wearing a tracker and accompanied by Emma, will head back into the field to lure out the terrorists.

It’s a catastrophic miscalculation. Tara agrees, trembling, and sets off for Piccadilly Circus station. But in the blind spot between stairs and platform, she removes her jacket — and the tracker — before vanishing. At that exact moment, the code she gave MI5 activates. Within seconds, the entire intelligence network goes dark.

The “bee” tactic, which David Cartwright had warned River about — the spy who stings twice before the fatal strike — comes full circle. Tara was never a victim. She was the infiltrator, executing the second stage of the destabilization plan: blinding MI5 and crippling the country’s defenses.

Meanwhile, at Slough House

Back in the chaos of Slough House, Shirley, Standish, and Roddy dig through his personal stash and uncover clues connecting Tara to every stage of the attack. River and Coe’s misadventures bring much-needed levity, but beneath the humor lies River’s inner turmoil. Jack Lowden shines here — his River Cartwright remains impulsive, brilliant, and haunted by failure, while grappling with the decline of his grandfather David (Jonathan Pryce).

Lamb, meanwhile, knows that the worst is yet to come. “Blinding the enemy” is only the beginning, and it feels as though MI5 is on the verge of being destroyed from within. The fact that the group is “Libyan” offers little comfort — he’s determined to uncover which disillusioned leader is truly pulling the strings.

Heading into the finale

With MI5 systems crippled, Tara vanished, and the country in peril, Slow Horses ends its fifth episode on a razor’s edge. What started as a messy internal feud has evolved into a full-blown national crisis. And the question that remains — equal parts hopeful and tragic — is simple: can the Slow Horses save the day one more time?