Arriving at Camp Bastion in Helmand Province, the superstar gets an invaluable insight into life in camp for our servicemen and women.
He faces some daunting tasks, including joining the air traffic control team to see aircraft operations in action, stepping into the driving seat of a huge HET, and heading out on a 6am run with the troops.
He also makes a heartwarming visit to the vigil site, paying tribute to those British troops killed in action over there.
The climax of his trip sees Gary give back with a massive concert for the soldiers, sailors and airmen serving their country.
Gary Barlow: Journey To Afghanistan, ITV, 9pm