When an attempt to extradite a group of infamous convicts from the Philippines to South Korea is foiled by an airport bombing, the authorities instead commandeer the ‘Frontier Wolf’ cargo freighter to carry out the transfer. Trapped inside the vessel under the watchful eye of its cruel captain, the prisoners hatch a merciless plot for escape. But in the ensuing bloodbath of violence and carnage, neither side realises that a gang of murderous criminals might not be the deadliest cargo on the ship…