They go by the call sign ‘Dustoff’. More formally, they are known as the C Company 1-168th Medevac (Air Ambulance) attached to the 159th Aviation Brigade, 101st Airborne Division. From remote forward operating bases (FOBS), to the dun-coloured emptiness of the desert and snowy Hindu Kush mountains bordering Pakistan, the Medevac helicopter "dust-off" crews are the first on the scene when a soldier goes down. For US and Afghan soldiers alike, they represent the last line of defence between life and death. With elections planned for August and the prospect of a bloody summer ahead as thousands of new US troops deploy in Afghanistan, the Medevac crews are expected to be busier than ever in the coming weeks and months. For three weeks we followed these pilots and medics out of their base in Jalalabad, flying their mercy missions into some of Afghanistan’s most volatile front line regions. During that time we witnessed missions to evacuate IED victims and soldiers wounded in fire fights. We spoke at length to pilots, medics, crew chiefs and surgeons about their work, fears, and the impact witnessing such human suffering has had on their own psyche and lives.