That day is seared into the memory of every human being on the planet: the day the world changed. First came the attack on the Philippines. Within days they spread, as though appearing out of nowhere, striking out at more islands, forging a foothold in the South Pacific. Then came the first attack on U.S. soil - Los Angeles - and the reality became clear: our world was at war once again, but this time with an enemy from beyond our galaxy. Now, months later, the fate of the world hangs in the balance as a mission to strike at a key enemy installation deep in enemy territory goes terribly wrong, and the Marines of the 15th Expeditionary Unit are scattered across the island of New Britain, leaderless, and facing impossible odds. Pacific Theater is the story of those Marines: fresh recruits who journey from their homes across the Pacific to the front lines. It is the story of John Blake, a charming Californian surfer who must find the strength to become a leader, Tracey Gleeson, a physics student from Brooklyn determined to fight in honor of her fallen brother, and Chris Jackson, the troubled Lieutenant whose deep psychological scars threaten to tear his platoon apart. Each of them must find the courage to fight on as war rages throughout the Pacific Theater, and the trauma of battle pushes them all close to breaking point.