This book tells in a popular form about new discoveries, ideas and hypotheses in the field of studying double stars. The sequence of presentation corresponds to the successive stages of the life (evolution) of double stars. But the story about each stage is based on the example of a specifically observed binary system with a description of the living history of its discovery and research. At the same time, the essence of the main astrophysical methods for studying binary systems is revealed. For everyone who is interested in astronomy, including schoolchildren, students, and teachers.