In late August of 2011, Shahbaz Taseer was driving to his office in Lahore, Pakistan when he was dragged from his car at gunpoint and kidnapped by Islamic extremists.

Just seven months earlier, his father, Salman Taseer, the governor of Punjab Province, had been shot dead by his guard for speaking out against Pakistan's blasphemy laws.

For almost five years Shahbaz was held captive, moved ever-deeper into the lawless Hindu Kush, frequently tortured and forced to endure extreme cruelty, his fate resting on his kidnappers' impossible demands and the uneasy alliances between his captors - the Islamic Movement of Uzbekistan (IMU) - and the Taliban and ISIS.

Lost to the World is the remarkable true story of Taseer's time in captivity, and of his astonishing escape. It is a story of extraordinary faith, bravery and sorrow, with moments of kindness and humour offering a hopeful light in the dark years of his imprisonment.

By turns immensely personal and surprisingly universal, Shahbaz Taseer's story is a testament to the enduring power of the human spirit.