In order to acquire a Pissarro, Hemlock agrees to carry out a couple of "sanctions" (contract assassinations targeted specifically against killers of American agents). The first one is easily dealt with in Montreal. For the second, he will need to join a group of climbers who are about to attempt the north face of the Eiger, a particularly difficult challenge that Hemlock has tried before and failed. Hemlock goes back into training and eventually climbs the mountain with the team that he believes includes his would-be victim — whose identity he will have to deduce on the mountain itself. Poor climbing conditions disrupt the climb and lead Hemlock to the discovery that his target is someone other than he had expected.
