Nellie was very concerned that her father, Professor Rakitin, had married for the third time - to a girl younger than his own children! – and she turned to Astra Eltsova, who is engaged in private investigations. It turned out that the woman was worried for good reason: a few days later Nellie was found murdered... Professor Rakitin was studying the history of ancient Babylon, and Astra realized: the circumstances of his daughter’s death were reminiscent of the Sumerian myth about the descent of the goddess Ishtar into the underworld. Astra learned that Nellie had lost the “star of Ishtar” - an exquisite gold jewelry with lapis lazuli, once stolen from the excavations of Babylon. But who conceived and committed such a sophisticated crime?