Episode 6 of Season 4 of "Slow Horses" commences with the devastating aftermath of the assault on the Dogs, leaving Emma Flyte miraculously alive yet reeling in a state of profound shock. Diana's urgent call is answered by Emma's tremulous voice, recounting the horrors that unfolded and the grim news of River's abduction. Claude, now at the helm of MI5 operations, issues a ruthless 'shoot-to-kill' directive, leaving Diana with little recourse despite her misgivings.
Meanwhile, River finds himself face to face with Frank in a bustling bar, a confrontation that has been brewing throughout the season now laid bare. Frank's overture is a thinly veiled attempt to reconcile with his son, dangling the prospect of a joint venture as bait. He recognizes River's raw talent but seeks to harness it for his own ends. However, River is no easy mark, unmasking the true nature of Yves' demise as a desperate plea for assistance, not part of any calculated plan.
Frank, a cunning adversary, swiftly disarms River of his phone, sensing the boy's attempt to summon aid. In a moment of vulnerability, Frank offers a ticket to Europe as a fresh start, but River's response is unequivocal, a defiant dismissal. Despite River's plea to spare David, Frank's merciless ambitions remain unchecked.
Louisa, meanwhile, is on the prowl, entrusting Roddy with tracing the origin of the fateful call while she races to Gresham Street, the epicenter of the attack. There, fate intertwines as she encounters Emma, and together, they embark on a perilous mission to the docks, determined to save River from the Dogs' clutches.
Jackson Lamb's solitary quest leads him to Sam's abandoned apartment, where he discovers the grim reality of Sam's fate. Uncharacteristically, he leaves the cash untouched but indulges in the alcohol, a somber gesture amidst the tragedy.
Patrice, fueled by Moira's cryptic voicemail revealing David's whereabouts at Slough House, storms the premises, igniting a chaotic gunfight as the team struggles to evade capture. Amidst the turmoil by the docks, Frank's treachery reaches its climax as he slips a grenade into River's jacket, only for Louisa's quick reflexes to avert disaster by defusing the explosive at the last moment.
Marcus, his gun securely regained, valiantly shields the others as Frank stealthily makes his escape towards St Pancras station. MI5's pursuit is relentless, yet River, recalling Frank's cryptic words, hypothesizes that he might be biding his time rather than fleeing. With uncanny precision, River tracks Frank down, earning the latter's admiration for his prowess.
Meanwhile, Patrice breaches the Slough House office, only to be met with a swift knockout by Jackson Lamb, with Shirley contributing her fair share of blows. Tragically, amidst the chaos, Marcus falls victim to the violence, his life extinguished. JK, with a steady hand, dissuades Shirley from finishing Patrice off... only to carry out the deed himself.
Diana interrogates Frank, who exudes a confident nonchalance, secure in the knowledge of his failsafe plan. His arrest seems inconsequential, as he anticipates a swift release. Predictably, Diana is notified of developments, including the assault on Slough House, where Jackson Lamb stands, delivering grim tidings. The envelopes Molly possessed were more than mere cautions; they were damning letters exposing MI5's darkest secrets.
Frank wields this leverage, demanding release or else the sordid affairs will be exposed to the world, a burden that would inevitably crush Claude Whelan. At MI5 headquarters, Moira exerts her power over Claude, exploiting the Galahad debacle to regain her position (and a salary hike), while David is reluctantly placed in a home. River's heart is torn asunder by this betrayal of his promise, but understands the necessity, though it tears him apart.
Jackson summons River to a nearby pub, where they sign a document attesting to River's movements, a solemn act amidst the tumultuous season. As the dust settles, the two men find solace in each other's company, sharing a drink in a profound silence that encapsulates the weight of all they've endured.
