This is the untold story of the forgotten Secret Service heroes of World War II: members of the elite MI-14 division, the intelligence group in charge of carrier pigeon operations. Pigeons such as Winkie, G.I. Joe and Mary of Exeterwere dropped behind enemy lines by parachute and took part in some of the most daring missions of the war. With testimony from surviving bird trainers and access to recently declassified documents, this film reveals the crucial role pigeons played in saving the lives of soldiers and airmen, and the epic battles they fought against killer falcons. Using the latest scientific research, the film also explores the pigeons' instinct for survival and the sophistication of their navigational skills.