Douglas Brunt’s The Mysterious Case of Rudolf Diesel tells the story of Rudolf Diesel, the German inventor of the internal combustion engine. After the Industrial Revolution, industry had become king, and Diesel’s groundbreaking invention produced more power, used cheaper fuel and didn’t require a team of laborers to keep running. The railroad industry immediately adopted the diesel engines, but its use in naval vessels also played a key role in the tension between European nations—particularly Germany and Britain—that eventually erupted into World War I.

Prior to WWI, Germany had a weak navy, especially compared to Britain's. Despite a massive naval expansion, Germany still failed to compete with the Royal Navy and instead began focusing on another type of vessel: submarines. Called U-boats or unterseeboots in German, this type of underwater ship had been previously built and utilized, most famously by the Confederacy during the American Civil War ...