Staff at St George's Hospital tackle one of their most dramatic emergencies when 60-year-old rail worker Alan is airlifted to the helipad after being hit by a high-speed train. A CT scan reveals he has suffered multiple fractures and loss of blood flow to his right arm. Without circulation he will lose the limb, so the medical team tries everything to save it, including complicated surgery. Meanwhile, 95-year-old Betty is brought in after experiencing breathing difficulties at home, and retired engineer James, 63, has a nasty cut to his head and weakness in his arms following a tumble down the stairs