Like a heaven-sent bird that flutters into the life of detective Andrei Pryaznikov, a beautiful and very rich girl with a strange name, Dirli-Du, arrives. Just at the moment when Pryaznikov is investigating the murder of banker Gleb Baturksky. Among the suspects are the victim’s best friend, his ex-wife, and the bank’s modest employee Alena Dmitrieva. Alena disappears without a trace. Her diary, attached to the investigation materials, reveals the veil of a secret surrounding the banker’s murder. Pryaznikov suspects that Alena and Dirli-Du are somehow connected.