Fritz-Julius Lemp tracked the approaching ship in his submarine's periscope. It had become a silhouette barely distinguishable against the darkening twilight sky, but Lemp was close enough to see the foaming white wave thrown up by its bow. He smiled when the spray arched higher, signaling the ship had begun changing course again.

"You're right on schedule," he said to the image in his eyepiece.

Lemp's pulse quickened with the knowledge that his war was about to begin . . .

On September 1, 1939, the passenger liner Athenia set sail from Glasgow for Montreal by way of Belfast and Liverpool. She carried 1,100 passengers, nearly three-quarters of whom were women and children. On September 3, Athenia was torpedoed by a German submarine. In Without Warning, author Thomas C. Sanger tells the harrowing story of the sinking of the Athenia from the perspective of eight people: six passengers, Athenia's chief officer, and the commander of the German U-boat.

Based on accounts written by passengers, personal interviews with survivors and descendants of survivors, books, newspaper stories, and original documents, Without Warning honors the memory of Athenia's passengers, both living and dead.