In Tallinn, in St. Olaf’s Church, an arrow is driven into the organist’s back. And at the museum of the Brotherhood of Blackheads, a foldable golden altar made by Jan van Eyck disappears. Klim Ardashev will have to figure out what connects four notes written into the score of the deceased musician, an ancient Roman epitaph on an old crypt, and a battle from the Livonian War. The investigation is complicated by the murder of a Soviet diplomat, the arrival of an old Yalta acquaintance, and the docking of the steamer “Paris Commune” carrying gold from Petrograd. And that’s still far from all the obstacles standing in the way of the private investigator in August 1920.