The documentary film is based on the materials of the Pacific Historical and Geographic Postal Cinema and Radio Expedition "Maritime Heritage of the Primorsky Territory" and the world's first Postal Radio and Telegraph Historical Adventure Experiment POSTVENTURE. The experiment reconstructed 40 different methods of mail delivery: underwater, underground, balloon, space, bicycle, scooter, ship, barrel, bottle, alpine and many others - today it is a massive and most diverse mailing list in the world.