In the Southern Helmand Province of Afghanistan, outnumbered American forces are relieved to see British air support arrive to aid in their fight against Taliban fighters. The plane releases a missile, but a British computer hacker on the ground changes the weapon's course to hit U.S. troops.
Section 20 launches an investigation back in London and discovers that encryption codes were hacked by Gerald Baxter, a former missile guidance engineer. Assigned to locate and extract Baxter, John Porter meets an Afghan Governor under the pretence of selling weapons and encryption codes to future International Security Assistance Force missiles. Arousing suspicion, Porter is kidnapped and taken to a Taliban camp where Gerald Baxter, otherwise known as Josuf Mohammad, greets him. Both men are captured by American troops, but manage to escape during transport. Baxter reveals that he used to work for the Americans but they now want him dead. He convinces Porter to head Pakistan to meet with Zahir Sharq, Baxter's boss who will want to purchase the encryption codes.
Hugh Collinson meets with Frank Arlington, the U.S. special security attach in London. Arlington denies knowledge of Porter's existence and insists that Baxter was captured alone. Arlington eventually admits that he doesnt have the two men to trade, and Collinson realizes neither country knows where the men are.
Porter and Baxter arrive at Sharqs base in Pakistan. Porter is restrained when Baxter outs him as a British Special Forces operative. Listening in on a conversation between Sharq and Frank Arlington, Baxter learns that Sharq is willing to trade the two men for information and support from the Americans.