To impress the girl, eleventh graders Vitaly and Sasha tell her that they have invented a device that will revolutionize science. Unexpectedly for them, Larisa asks them to show it, and then the guys hastily begin to drag parts and pieces of various electrical and radio devices from the dump of the dacha village and haphazardly connect them together, hoping that the girl does not understand anything about this and will accept the one they made at random unit for a miracle of technology. But during the tests it turns out that the device works, and the guys find themselves in a parallel world...