The long-awaited thriller from one of the most mysterious authors of the genre. Art history professor Dr. Jonathan Hemlock has extremely expensive hobbies - collecting paintings and mountaineering. So you have to earn money on the side - to sanction traitors on the instructions of intelligence (a sanction in the language of professionals is called murder). The last task is the most difficult - to eliminate the traitor, a participant in the ascent of the Eiger, one of the most dangerous peaks of the Alps. The agent who needs to be authorized is among three climbers preparing to climb the forbidding northern slope. Which of them is the target is unknown. In general, “even if he’s in a relationship with you, you’ll understand who he is.” A smart detective plot and a very caustic satire on the topic of intelligence and art, with well-written ascents of climbers.