Popular science account of the search for extraterrestrial intelligence. It tells about methods of searching for extraterrestrial civilizations, about experiments to search for signals. The astronomical, biological, and philosophical aspects of the problem are considered. The book is accessible to readers with secondary education. It does not require any special knowledge. At the same time, this is not an easy, entertaining read. It requires some effort from the reader. This is an attempt at a serious conversation, co-reflection with the reader.