On 25 January 1944, along with three other commandos, Major Thompson was sent on a parachute landing mission to establish a link between the British staff and the Bulgarian partisans led by Slavcho Transki; he landed near Dobro Pole, Macedonia. The commandos carried a radio to keep in contact with the staff in Cairo, Egypt and Bari, Italy, but it broke down. On 23 May, Thompson took part in the clash at the village of Batuliya between the Bulgarian Gendarmerie and the Second Sofia Brigade of National Liberation of the partisans. He was wounded by the gendarmerie forces, captured and, after a defiant speech in Bulgarian at his show trial, was executed by firing squad in the nearby village of Litakovo.