In the rest of Europe World War I has started but Sweden is still neutral despite her German sympathies. Lars Tobiasson-Svartman is a naval engineer charged with the task of measuring the depth of the sea in the Swedish archipelago to find speedier navigable channels. This isn't just a job - it's an obsession for Tobiasson-Svartman, whose ambition is to find a depth that can't be measured. The act of measuring is an obsession for him - he's constantly measuring the distances between himself and other people. Death seems to follow him around; there are three whilst he's making his first series of soundings, including the captain of the ship.