Slow Horses Season 5 finale recently unveiled the truth about Jackson Lamb's deformed feet of Jackson Lamb which have formed his personality and character all this time. The scene justifies his hatred for MI5, or why he never gets off his shoes during casual meetups. The Feet Story also gives us a window into Jackson Lamb's past, which has been a mystery all this time, given the powerful mind he has, but still counted among the failed troops.
In the earlier episodes of Slow Horses season 5, Lamb tells his team a chilling story of a British spy who was captured by Russia and tortured brutally by them. The finale reveal confirms that the legendary spy is none other than Lamb himself. His foot is scarred and burnt from the torture he suffered, while still being silent about the state secrets.
Slow Horses Season 5: Why does Jackson Lamb have deformed feet?
Slow Horses Season 5 reveals the reason behind Lamb's deformed feet, connecting it to his past when he was captured by Russians and tortured. His interrogators were desperate to make him talk and brought in the woman he loves and carrying his child, while killing her in front of him. The spy for the nation and his integrity still stayed silent under unimaginable pain and loss. He protected state secrets at the cost of humanity.
In episode 3, Lamb presented this story as a lesson in endurance to his team. He was encouraging his team to improvise under pressure when they were trapped by MI5 bureaucracy. The way he narrated the story felt personal and seemed hard to be just a fiction. The tone, the detail, and the grief behind his words were denying the fact that it is merely a story and not a lived experience.
It was in the finale that the camera lingered to show the close-up of Lamb's foot, which is scarred and burnt, connecting him directly to the spy from his story. The show was building up the mystery of Lamb's past for a long given his wisdom and hatred for MI5.
Here is why the season 5 finale revelation of Slow Horses matters

Slow Horses has often shown Lamb's body language to imply unseen pain. He winces when sitting down or standing up, and barely opens his shoes, even in intimate or casual meetings. Moreover, his habits related to alcoholism and hatred for MI5 also seem valid after the major season 5 reveal. He has always used wisecracks and slovenliness as a shield to bury his guilt and grief. He is cold towards some younger agents; it isn't because of apathy but self-protection, as he has seen what loyalty costs. He is loyal to Slough House despite facing insults, as he knows what it means to be discarded by the system.
Despite being the legendary spy who lost his everything to keep up the state secret against the enemy is working among a group of failed agents. He has always seen delegating any physical task to his agents while also barely getting involved in field operations, which has a lot of times led to his mockery. Moreover, revelation of his past now also answers to his disgust for bureaucratic hero-worship and his visceral reaction to Russia-related missions.
Slow Horses Season 5 finale revelation has added several layers to Lamb's physique and opened a new narrative about whether his past would come in a new form, or if silent self-destruction is the only way for him.