The plot of "Front Mission" revolves around OCU captain Lloyd Clive. An OCU reconnaissance platoon led by Lloyd is assigned to investigate a USN munitions plant in the Larcus District, located on eastern Huffman Island. Upon reaching the premises, the platoon is ambushed by USN wanzers led by an officer named Driscoll. He quickly ambushes Karen Meure, Lloyd's fiancée, and destroys her wanzer. As the two forces engage in battle, Driscoll detonates explosives inside the plant and escapes. The USN accuses the OCU of the attack, later known as the Larcus Incident, but the OCU insists that the incident was a set-up. Both sides soon declare war, setting off the 2nd Huffman Conflict. The OCU pins the blame of the incident on Lloyd's platoon, discharging them from the military indefinitely. One year later, OCU colonel Guri B. Olson seeks him out at a wanzer fighting arena in the town of Barinden. Dangling the prospect of killing the person responsible for Karen's death, he manages to recruit Clive to the "Canyon Crows" mercenary outfit. With the Canyon Crows, Lloyd is assigned to help the OCU military reverse its fortunes and win the war.