Mohamedou Ould Salahi and one of his former guards, Steve Wood, reunite in Mauritania 13 years after last seeing each other, rekindling an unlikely relationship that profoundly changed their lives.

Mohamedou was a prisoner at Guantánamo Bay for 14 years. During his incarceration he was subjected to torture and solitary confinement, but never charged with a crime. His memoir, Guantánamo Diary, became an international bestseller and was adapted into the film, The Mauritanian, starring Tahar Rahim and Jodie Foster.

My Brother's Keeper is BAFTA longlisted for British Short Film 2021.

• Read exclusive extracts and listen to audio readings from Mohamedou's book on the Guardian.