Apple TV's Slow Horses has a knack for packing a punch in just six episodes per season. The spy thriller, based on Mick Herron's novels, keeps viewers on the edge of their seats with each new threat to Slough House, the dumping ground for MI5's misfits. Season 5, which wrapped last October, was no exception—delivering a whirlwind of chaos, betrayal, and a jaw-dropping revelation about Jackson Lamb. With Season 6 premiering today, September 16, here's everything you need to remember before diving back in.
A Season of Terror and Political Intrigue
Season 5 kicks off with a chilling scene: a gunman opens fire on a crowded city square during a mayoral campaign event. As the story unfolds, the Slow Horses uncover a terrorist plot aimed at destabilizing the UK government. The group's targets include disrupting transportation and planting a bomb at a zoo, but their ultimate goal is to assassinate a populist leader—initially believed to be far-right candidate Dennis Gimball (Christopher Villiers), who's running against incumbent Zafar Jaffrey (Nick Mohammed).
The terrorists also manage to hack into MI5's systems, thanks to Roddy Ho (Christopher Chung) being duped by a woman named Tara (Hiba Bennani), who he thinks is his girlfriend but is actually a plant. Meanwhile, River Cartwright (Jack Lowden) and J.K. Coe (Tom Brooke) accidentally cause Gimball's death in a bizarre paint can incident, throwing the operation into further disarray.
MI5's Power Struggle
After a system-wide outage, the Slow Horses manage to thwart the real attack on Mayor Jaffrey, but First Desk Claude Whelan (James Callis) is attacked during a run—until River saves him. In a classic villain move, Whelan tries to pin the blame on Slough House and threatens to shut it down. But Jackson Lamb (Gary Oldman) has a card up his sleeve: a recording of Whelan threatening Gimball before his death. Lamb blackmails Whelan into backing off, securing the rehiring of Molly Doran (Naomi Wirthner) and Roddy's reinstatement. The power shift culminates with Diana Taverner (Kristin Scott Thomas) finally taking over as First Desk, a role she's long coveted.
Lamb's Shocking Secret
Midway through the season, Lamb mentions an agent who was forced to watch his pregnant lover be tortured and killed, and who had his feet badly burned. In the finale, we see the soles of Lamb's feet—covered in severe burn scars. It's confirmed: Lamb was that agent. This revelation adds a layer of tragedy to his gruff exterior, making him a more sympathetic figure than we ever imagined.
What's Next in Season 6?
Season 6 promises a new threat: past and present Slough House agents are being targeted, and the team must figure out who's hunting them. Louisa Guy (Rosalind Eleazar) returns after her Season 4 departure, and River's father, Frank Harkness (Hugo Weaving), is back for more chaos. The biggest shocker? Sid Baker (Olivia Cooke), who supposedly died after Season 1, is alive! Her return is sure to stir up old emotions and secrets.
With its blend of sharp wit, intense action, and character depth, Slow Horses continues to be a standout in the spy genre. If you're looking for more gripping thrillers, check out our list of the best psychological thrillers or see why Apple TV's Silo is earning rave reviews. And if you're in the mood for something to fill the void between episodes, we've got eight shows to watch until The Pitt returns.
All five seasons of Slow Horses are available on Apple TV in the U.S., with Season 6 premiering Wednesday, September 16.
