Front Mission 2089: Border of Madness is set one year before the Second Huffman Conflict, at a moment when the island's fragile stability has already been compromised. A series of skirmishes in 2086 known as the Huffman Crisis intensified tensions between the O.C.U. and U.S.N. to the point where both supranational unions are now increasing their military presence and bringing in mercenaries from across the world. Those mercenaries are deployed along Mail River—the border dividing the island's two territories—on espionage and reconnaissance operations that neither side will officially acknowledge.