Episode 2 of Season 4 of "Slow Horses" kicks off with a fresh lens on the dramatic events at David's abode. River's sudden appearance finds David, stunned and clutching his firearm, confronted with a chilling sight: a dead ringer for River, the impostor, lying lifeless in the bathtub. Identified as Adam Lockhead, the doppelganger's presence fills David with paranoia, but River's swift response to a question known only to him alleviates some of the tension.
The uncanny resemblance is striking, yet the moment the impostor addressed David as "gramps," alarm bells tolled loudly. Adding to the intrigue, the tub's running water hinted at a sinister plan—to drown David after drugging him with diazepam discovered in the impostor's possession. A return ticket to France and a receipt from Le Blanc Russe café in Lavande further muddied the waters.
David promptly alerts Park, drawing the authorities' attention, but River recognizes the urgency of the situation. He orchestrates a swift and decisive move, ushering David downstairs while planting his own phone and passport on the deceased Adam. With a calculated shot to the head, River eliminates the threat.
Meanwhile, Jackson's deliberate lie and subsequent gunshot revelation betray his guilt. Aware of River's pursuit, he seeks to stall him by sending him to France, assuming a heroic yet reckless endeavor. Jackson's disdain for River's actions fuels his determination to uncover David's true whereabouts in France, though his attempts to extract information from David prove futile.
Back at MI5, Claude's rehearsed speech falls flat as Diana's attention is elsewhere. Amidst signing paperwork, Claude pompously declares his intention to shake things up, revealing the very pitch that landed him his post. Diana delves into Robert Winters' background, uncovering him as one of their own—a "cold body" from the twilight of the Cold War, a term referring to individuals equipped with false identities and authentic documents.
Giti stumbles upon this revelation, but Diana swiftly dismisses its validity, erasing all traces from the system. When she informs Claude, his impulse for transparency is thwarted. She confesses that among the documents he signed earlier was a control and command (C&C) order, tricking him into becoming an unwitting accomplice in the cover-up. Diana's unwavering commitment to "extinguishing fires daily" leaves no room for Claude's meddling.
Jackson reappears in the office, his demeanor solemn as he unfolds the truth about River to the team. Reluctant to expose River's cover, he tasks Roddy with delving into every aspect of Lavande's existence. But little do they know, Slough House has welcomed an unexpected guest—a cleaner by the enigmatic name of Moira.
Over a tense meal at a restaurant, Jackson lays down the gauntlet to Moira. His tone unyielding, he demands that she never again cross the threshold of his office. He vows to uncover the reason for her assignment and ensure her swift removal, offering in return to leverage her access to their database in exchange for information on David Cartwright's trips to France and their purpose. To his surprise, she acquiesces.
Meanwhile, in France, River stealthily makes his way to the café, where a sympathetic worker whispers the identity of his impersonator and directs him to the mansion where he resides. Yet, unbeknownst to River, he's been marked. The masterminds behind the bombings are cunning, and one of their agents arrives at David's residence, inquiring about the murder. Upon confirmation that it was River, not David, who perished, the agent phones his superior, his mind already turning to their next target.
Unaware of the intricate web woven around him, River arrives at the mansion, determination etched on his face. He forces entry and commences a thorough search, his eyes scanning every corner for clues. Upstairs, in what appears to be a childhood sanctuary, he stumbles upon a painting, its image seared into his memory as he snaps a photo. His investigation leads him to the attic, where, amidst a sea of books, he finds a photograph—a chilling image of Robert Winters, the man from the car, presumably his kin, alongside the elderly figure he had heard on the phone.
As he descends the stairs, disaster strikes. The mansion is engulfed in flames, and River walks straight into a trap. He's tackled to the ground, his throat threatened with a vice-like grip, until the elderly man from the car, River's relentless pursuer, emerges with a shotgun, firing a deafening warning shot before spiriting River away into the night, their destination a mystery.
