October 1914: the destroyer Svea emerged from the Stockholm archipelago bearing south-south-east. On board was Lars Tobiasson-Svartman, a naval engineer charged with making depth soundings to find a navigable channel for the Swedish navy. As a child Tobiasson-Svartman was fascinated by measurement; nothing is as magical as exact knowledge. His instinct for his profession is reflected in his comfortable domestic life with his wife - herself meticulous in every detail. Close to the waters where soundings are taken Tobiasson-Svartman alights on a barren skerry, presumed uninhabited, and is surprised to discover an unkempt young woman, Sara Fredrika. Despite her almost feral appearance, something about her strikes him to the core. The mission is a success and the Svea returns to Gothenburg. Tobiasson-Svartman, however, remains haunted by this chance encounter; his equilibrium has been disturbed, and he is now compelled to find any pretence to return to the remote islet. In Depths Mankell confirms his status a writer beyond the crime genre. By delving deep into the male psyche, he has produced a novel both as tense and compelling in every way as the Wallander series, but also powerful, moving and ultimately tragic.