During the war, the Germans took pedigree horses from the USSR, among which was Yermakov's favorite. After the war, he managed to find her and return, but the tribal certificate was lost. And now, forty years later, the granddaughter of this horse - the magnificent racing mare Secunda - is being sold for a pittance at an international auction to a certain Baron von Ritter. Ermakov guesses who owns the "lost" document.