How the Allied troops of Paiforce (Persia and Iraq Force), created in 1942, carried Allied supplies overland to Russia from the Persian Gulf.

(Reel 1) In 1942 Russia needed supplies badly. Britain and the US delivered most of these supplies by sea (ships are seen being unloaded); soon road and rail routes through Persia (Iran) was opened. Basra became a teeming port: here, trucks are put together at a British vehicle assembly unit. The trucks become a supply convoy, which sets off. On the Tigris river, barges deliver supplies, passing over the Hull bridge which has a submersible section. At Kut, the barges are transferred to the US-controlled Trans-Iranian Railway. At the Anglo-Iranian Oil Company's refinery in Abadan, fuel is canned prior to loading onto trains. The railway has 220 tunnels, so special diesel electric locomotives are used to minimise smoke. En route, Indian troops guard supplies from "pilfering local tribesmen"; one of them plays with a bear cub. The train picks up the supplies from Kut and continues to Khanagin. Here, British troops act as guards: men inspect heavy weapons. At the British camp, soldiers set up traps for insects, carry out routine tasks (peeling potatoes) and hold a concert. "Time hangs heavy": the waiting troops receive letters from home, eat in the mess tent. Indian troops carry out vehicle maintenance and indulge in "their favourite sport", wrestling. Equipped with warm clothing, the Indians prepare to drive convoy (of US GMC 6x6 two and a half tonners) through mountain passes to pick up supplies from the train. The trucks are loaded straight from the train in "only 15 minutes - surely a record anywhere in the world". (Reel 2) The trucks set off from Khanagin on a fully built road. In the mountains, clearance gangs keep the road clear of debris, and military police direct traffic. At higher levels, there is snow to be cleared. Sappers and signallers keep telegraph lines open. A Military Police post at the summit of the Shah Pass: British and Indian troops enjoy tea and cigarettes. The convoy continues to lower altitudes; a remote hospital treats accident victims. Trucks roll into Russian camp; Red Army officials check paperwork. Most of the trucks will return but some will stay with the Russians as aid (scene of Chevrolet truck being serviced). The handover takes place, and Russian soldiers relax, dancing to balalaika. Stock footage of tanks and other matriel demonstrates the large amount of aid which has been given to Russia since the supply lines opened. Fireworks display in Moscow: commentary praises the men who keep the supply lines open "to help win the war against Germany".