The series primarily focuses on the soldiers of the 4th Infantry Division of the Philippine Army and their actions during combat. Through multiple perspectives, the story focuses on these soldiers, mainly: Alex Marasigan (Gerald Anderson), an IT expert who quits his desk job and joins because just like his brother, he wants to serve the country, Abraham "Abe" Kamlun (Carlo Aquino), a Tausug Muslim man, who, despite his family's opposition of the move, joins the Army nonetheless, and Michael Mendoza (Nash Aguas), a boy who joins the Army to provide for his family. The series also focuses on their Moro separatist adversaries, led by Saal Alhuraji (Sid Lucero), also known by his nom de guerre Abdul Waajid, who seeks to avenge his father who was killed by the military.