In the weeks following the attack on Pearl Harbor, Robert Leckie attends church and runs into his longtime neighbor Vera Keller. Leckie, having enlisted in the United States Marine Corps, promises to write to her while overseas. Meanwhile, John Basilone and his fellow noncommissioned officers, Manny Rodriguez and J.P. Morgan, learn from Chesty Puller that the Marine Corps will be entering the Pacific Theater. They attend a Christmas dinner with the Basilone family. In Mobile, Alabama, childhood friends Eugene Sledge and Sidney Phillips say their goodbyes as Phillips prepares to depart for boot camp. In August 1942, the Guadalcanal Campaign begins. The Battle of the Tenaru and the Battle of Savo Island are depicted.