River Cartwright is a British MI5 agent who works at Slough House. He is played by Jack Lowden in the series Slow Horses. River was born on 10 May 1990 and raised by his grandfather, David, after his mother left him. He has a complicated background and struggles with his career in intelligence, but he is determined to prove himself and make a difference.

Trivia/Facts

• River Cartwright was born on 10 May 1990 to Isobel Cartwright. He was raised by his grandfather, David Cartwright, a former senior MI5 official. Isobel left after giving birth, which left River to grow up without his mother. He was given the name River during her hippy phase.
• Before the events of Slow Horses, River was close friends with James “Spider” Webb. They went through training together to join the Security Service. River’s initial training included an exercise where he had to tail Deputy Director-General Diana Taverner. This experience highlighted his skills and determination as a new agent.

Gary Oldman and Jack Lowden in Failure’s Contagious (2022)

• In the episode titled “Failure’s Contagious,” River is at London Stansted Airport with tactical agents. He is instructed to find a specific target but misidentifies him due to poor communication. As he chases the wrong man, an alarm goes off, leading to an evacuation. River discovers that the target he is chasing is carrying a bomb.
• River often feels frustrated with his career while working at Slough House. He confronts his boss, Lamb, expressing uncertainty about his role. Lamb belittles River, suggesting he should quit if he feels out of place. This interaction adds to River’s feelings of inadequacy and confusion about his career path.
• River learns about Hobden’s activities and becomes determined to investigate. He approaches Sid to discuss Hobden and his potential threats. Despite Lamb’s dismissal of their concerns, River and Sid decide to take matters into their own hands. Their investigation leads to discovering a possible hostage situation related to Hobden.
• While investigating, River witnesses Sid being shot, which shakes him deeply. He confronts Lamb about the situation, who is aware of River’s connection to Sid. This incident serves as a turning point for River, pushing him to take more decisive actions. River becomes determined to uncover the truth and protect his colleagues.
• River often finds himself at odds with his team members, especially regarding their trust in Lamb. He expresses confusion about certain decisions made by Lamb and the group’s dynamics. As tension builds, River feels the weight of responsibility for his team’s safety. This leads him to take risks in pursuit of the truth.

Dustin Demri-Burns, Jack Lowden, and Rosalind Eleazar in Bad Tradecraft (2022)

• River’s determination culminates in a series of dangerous encounters as he seeks to rescue Hassan Ahmed. He shows bravery by intervening during critical moments, even putting himself in harm’s way. River’s actions reveal his growth as a character, transitioning from uncertainty to a more proactive role. He learns the importance of teamwork and trust in high-stakes situations.
• After the intense events, River reflects on his experiences and relationships with his colleagues. He realizes the complexities of loyalty and deception within MI5. With his grandfather’s advice to keep a low profile, River contemplates his future and redemption. His journey illustrates the challenges faced by those working in intelligence and the personal sacrifices involved.
• As River continues to navigate his role at Slough House, he remains focused on proving himself. His experiences shape him into a more capable agent, driven by a desire to protect his colleagues. River’s journey is one of self-discovery, resilience, and the search for purpose in a world filled with uncertainty. His character arc reflects the struggles of balancing personal ambition with the realities of espionage.

River Cartwright’s Relationship with Other Characters

• James “Spider” Webb: River is close friends with Spider. They trained together to join MI5. Their friendship helps them support each other. However, their bond can be tested by work challenges.
• Diana Taverner: Diana is River’s boss and represents authority. He respects her but sometimes feels frustrated with her demands. Their relationship is tense because of her high expectations. River has to balance his feelings of respect and frustration.
• Jackson Lamb: River’s relationship with Lamb is complicated. Lamb often criticizes River and makes him feel insecure. Despite this, River learns important lessons from Lamb’s tough love. They show the struggle between a boss and his employee.
• Sid: River cares a lot for Sid. They work together and share their struggles at Slough House. He feels very protective of her, especially when she gets hurt. Their bond grows stronger as they face challenges together.

Jack Lowden in Slow Horses (2022)

• David Cartwright: David is River’s grandfather and gives him guidance. They talk about River’s career and personal issues. David helps River understand the intelligence world. Their relationship is important for River’s growth.
• Roddy Ho: River’s friendship with Roddy is mixed. Roddy is funny, but River sometimes finds him frustrating. They still work together and help each other. Their different styles show how diverse the team is.
• Hassan Ahmed: River wants to protect Hassan and help him. He gets involved in trying to rescue Hassan, showing his sense of duty. River’s actions highlight his commitment to others. Their relationship shows the risks of their work.
• Jed Moody: River feels suspicious of Moody’s actions. After Moody’s death, River reflects on trust in the team. Their brief interactions highlight the tension in their relationship. This loss affects River deeply.
• The Slow Horses: River has mixed feelings about his team at Slough House. He often feels frustrated with them but learns to appreciate their skills. Working together teaches him about teamwork. Their relationships are important for River’s journey.