In Dead Wake: The Last Crossing of the Lusitania, writer Erik Larson traces the Lusitania’s final journey across the Atlantic Ocean. The Lusitania is a British passenger liner owned by the Cunard Steamship Company. First sailing in 1907, the Lusitania quickly sets records for the fastest journey across the Atlantic Ocean, stealing the coveted Blue Riband away from Germany.

Dead Wake follows the Lusitania’s final journey, which took place during the first week of May 1915. One year prior, World War I breaks out in Europe, and Germany aggressively seeks to expand its power by invading and conquering France. The conflict quickly splits into two sides. France, Britain, and Russia form the Allies; and Germany and Austria-Hungary form the Central Powers. Germany and Britain quickly become embroiled in a deadly naval warfare. Germany’s U-boats (or submarines) prove to be particularly adept at destroying British warships. In the months before the Lusitania’s final departure, German submarines have begun to target neutral merchant ships more often, placing the lives of innocent civilians at risk. Though these attacks have started harming American citizens, President Woodrow Wilson remains unwilling to enter the war and fight Germany because he hopes to remain neutral and avoid conflict.

The Lusitania’s captain for its final voyage is William Turner, an experienced officer who previously set the Lusitania’s record for fastest round-trip journey between New York and London. On May 1, 1915, the day of the Lusitania’s departure, the Germans publish an advertisement in American newspapers announcing that any British ships—even merchant ships—are vulnerable to German attack. Many readers interpret the advertisement as a warning that specifically targets the American passengers boarding the Lusitania. However, the Lusitania’s passengers are unconcerned by the warning because they believe that the ship is impervious to submarine attacks.

At the same time that the Lusitania sets sail for Liverpool, a German submarine, the U-20, is ordered to patrol the waters between Britain and Ireland. The U-20 is commanded by Walther Schwieger, a talented submarine captain known for his ruthlessness in pursuing targets. The British Admiralty tracks the U-20’s journey through its secret Room 40—the name for an operation that intercepts and decodes German naval communications. The Admiralty tracks the U-20 as it sails around the coast of Ireland, firing and destroying several British ships as it travels towards Liverpool. Though the Lusitania will soon sail through the same waters, the Admiralty does not send a battleship to protect and escort the Lusitania to safety.

As the Lusitania enters the final leg of its journey on the morning of Saturday, May 7, Captain Turner receives vague warnings from the British Admiralty about submarine activity in the waters around the Irish coast. Turner is unsure about how to proceed towards Liverpool, and he orders his crew to perform a maneuver called four-point bearing to determine the Lusitania’s exact geographic location. Unbeknownst to Turner, the U-20 is trailing the Lusitania, and the maneuver places the Lusitania directly in the U-20’s firing line. Schwieger seizes the opportunity and launches a torpedo at the Lusitania, successfully causing a massive explosion that sinks the passenger liner.

The Lusitania’s passengers and crew are ill-equipped for the torpedo attack, and their attempts to escape result in chaos. The Lusitania severely tilts to its side after the attack, making it difficult to access the ship’s lifeboats. Many of the Lusitania’s passengers die accidentally as they attempt to board the lifeboats. Others drown or develop hypothermia as they float in the icy waters of the ocean. Though rescue ships arrive three hours after the explosion, many of the Lusitania’s passengers die before the ships arrive. The final death toll is 1,198 passengers and crew.

In the weeks that follow the attack, the British Admiralty attempts to blame Captain Turner for the Lusitania disaster, arguing that Turner improperly followed the Admiralty’s orders for avoiding attacks. However, the subsequent inquiry into the incident ultimately reveals that Turner acted to the best of his abilities and declares that Germany is completely responsible for the deaths of the Lusitania’s victims. After the Lusitania disaster, President Woodrow Wilson is incensed by Germany’s attacks on neutral merchant ships, which have caused the deaths of innocent American lives. However, he is still unwilling to enter the war. Instead, Wilson issues a statement that denounces Germany’s submarine warfare practice. The statement eventually causes America to enter the war and join the Allies in April 1917.