This article contains spoilers for the season 6 finale of Slow Horses and Mick Herron’s Slough House book seriesIn the explosive finale of Slow Horses season 6, lives are lost and deals are made to protect the remaining joes of Slough House. After Jackson Lamb and his team get together to toast the joes who didn’t make it to the end of the season, it seems like things will be peaceful for a while, and with the villainous Frank Harkness, estranged father of spy River Cartwright, retreating to the shadows once more, there’s no reason to think otherwise.cnx.cmd.push(function() {cnx({playerId: "106e33c0-3911-473c-b599-b1426db57530",}).render("0270c398a82f44f49c23c16122516796");});But there are a couple of surprises in store for Jack Lowden’s character in the final, shocking moments of season 6. Just when he thinks he might get to be happy for a little while, the murky spy world delivers another stunning blow.Let’s take a closer look at what happened and what lies ahead for River when the story continues in Slow Horses season 7 and beyond, but please note that we will be discussing spoilers from Mick Herron’s Slough House book series in the latter part of this article. We recommend not reading any further if you want to remain completely spoiler-free on River’s fate.What Events Led to River’s Collapse?When Catherine Standish tells River at the church that she’s received a rather random phone call about a light on in his late grandfather’s house, River is reminded of a story he told missing spy Sid Baker before they parted ways. River had said he was always comforted that his grandfather left a light on when he expected River to visit, but now that he’d passed, River was saddened to find the house dark when he approached.Hearing that a light is on in his grandfather’s house, River suspects Sid is lying low there and signalling that she wants him to come meet her. The two romantically reconnected during the events of this season, and River is excited about the possibility of seeing Sid again. He rushes off to his grandfather’s house, where he sees Sid pottering around through a first-floor window.After entering the house, River hears Sid in the shower. He sets about boiling the kettle for tea or coffee, then senses the occasion calls for wine. He pulls out two nice glasses and a bottle, but he doesn’t even get a chance to finish pouring it out. He collapses horribly, and as the season comes to a close, we realize that something is terribly wrong with River.What Happens to River in the Books?Season 6 adapts the sixth and seventh books in Mick Herron’s series, Joe Country and Slough House, meshing together the stories of Sid’s return and what happens to Lamb’s other joes, but Slough House does indeed end with River being poisoned by Novichok, an extremely lethal nerve agent developed by the Soviet Union. In season 6, Diana Taverner and Lamb discuss its earlier use on British soil and how it destabilized the region’s geopolitics, prompting Taverner to retaliate against the Russians herself.When he arrives to meet Sid, River doesn’t realize that the two deadly Russian agents originally sent to kill Lamb’s joes have already been to his grandfather’s house and contaminated the front door handle with Novichok, and he is poisoned after he touches it to enter the property. In the next book in the series, Bad Actors, we learn that Sid has put herself in enormous danger by trying to save him and may have exposed herself to the agent.Both Sid and River survive the Novichok hit, but we don’t really discover their fates until the end of Bad Actors. River spends the book recovering and still isn’t back to his old self when we finally learn what happened. In Herron’s most recent Slough House novel, Clown Town, River continues to recover and gets drawn into a mystery linked to his grandfather while he waits for medical clearance to return to his MI5 duties, even as he debates whether he really wants to return to the spy life after all he’s been through.How Will River’s Story Affect the Show?You may have noticed that River doesn’t really show up in the now-traditional trailer for the next season at the end of the season 6 finale, so it’s entirely possible that the character will have a reduced presence in seasons 7 and 8 as he recovers from the Novichok poisoning. However, Slow Horses may not follow the exact story Herron tells in his books. The writers might change the story so River eventually dies, or they might leave his fate unknown until later in the season, much as Herron did in the eighth Slough House book. There have also been rumors swirling that Lowden has scored at least one high-profile role elsewhere. If those turn out to be true, Slow Horses might choose to phase out his character and put the spotlight on different joes at Slough House. Lowden could then return later to reprise River Cartwright, should his schedule and interest permit.When Will Slow Horses Season 7 Be Released?While we wait for confirmation on River’s fate and how the joes respond to his poisoning, we’ll be looking forward to the next two seasons of Slow Horses and finding out who else might emerge to make Jackson Lamb’s life more complicated.The show usually releases a new season around the same time each year, so we’d expect season 7 to arrive in September 2027.The post Slow Horses Season 6 Ending Explained: What Happened to River? appeared first on Den of Geek.