Slow Horses Season 5 on Apple TV+: MI5 Investigates a Mass Shooting as Slough House Faces New Threats

Apple TV+'s Slow Horses returns for a fifth season that leans deeper into workplace dark comedy while threading a timely thriller. The premiere centers on a mass shooting in a London apartment block connected to the reelection campaign of Mayor Zafar Jaffrey. Eleven people are killed before a sniper neutralizes the gunman and disappears. MI5’s Slough House is pulled into the investigation, testing the team's unorthodox methods as they juggle personal tensions with a case that could reach higher political levels.

Roddy Ho, headphones on and dancing to Robert Palmer, heads to Slough House, only to dodge danger when a white van races toward him. The attack on Jaffrey's campaign staff leads Shirley Dander to sense that Roddy was specifically targeted, a theory she presses on her boss, Jackson Lamb, with the help of Catherine Standish. Louisa Guy, on the cusp of a six-month leave, reveals to River Cartwright that she is leaving MI5 altogether, a development that unsettles him and leaves him to wonder what he will do without her. Emma Flyte leads the initial scene work, finding a spent cartridge and recognizing the shooter left a message. The investigation also places the spotlight on Dennis Gimball, a right-wing candidate in the mayoral race, while MI5's leadership, General Claude Whelan and Deputy Director Diana Taverner, move to shore up security for both campaigns.

Lamb's breakfast-table banter with Catherine highlights the show's blend of grit and humor. Oldman's performance anchors a crew whose competence is undeniable even as their personal flaws and office politics threaten to derail them. Season 5 has more room to explore the cases that tie the Slough House team to a broader conspiracy while leaning into the ensemble's chemistry that has kept the series fresh through multiple seasons. The developing relationship between Roddy and his new partner Tara adds a personal layer to the investigation that could pull at loyalty and risk as the plot progresses.

Although the show remains a workplace comedy at heart, the mass shooting thread amplifies the show's relevance in a world where political violence and security concerns dominate headlines. The UK’s gun laws and the mechanics of obtaining militarized weapons are part of the backdrop that the writers use to heighten stakes without turning the series into a straight action thriller. The connection between Slough House and the wider MI5 machinery complicates how the team operates, forcing them to navigate both the labyrinth of internal politics and external threats that could reach their doorstep.

Based on Mick Herron’s Slough House novels, with London Rules shaping Season 5, Slow Horses has traded some of its earlier lean ambiguity for more pointed thriller material while preserving the dry wit and deadpan delivery that defined its tone. The show’s concept of misfits using unorthodox methods to achieve results continues to set it apart from typical spy procedurals, a distinction that fans and newcomers alike may find appealing. In the current season, the balancing act between character-driven humor and high-stakes investigation remains the series’ defining trait, with Oldman delivering the level of cartoonish energy that has become a signature of Lamb’s leadership.

All five seasons of Slow Horses are available to stream on Apple TV+, which offers a seven-day free trial for new subscribers and an ad-free plan at $13.99 a month. The platform provides continuity for fans eager to see how the Season 5 mystery unfolds and how the Slough House crew navigate the threats now pressing in on their turf.