Lt. Col. Philip Locke is taken to an abandoned factory by his kidnapper, Real IRA member Mairead McKenna. Sgts. Damien Scott and Michael Stonebridge work to rescue their boss, taking hostage a Lebanese car salesman with ties to the al-Zuhari. The man gives up McKenna's location just as a hitman shoots him dead. After the boys take out the assassin, they discover that he's a member of the Russian mafia, a Vory-v-zakone. Section 20 is being targeted for killing Arkady Ulyanov's son in Colombia.
McKenna offers to tell Locke who killed his son in exchange for the access protocols to NATO's databases. Locke is shaken, but refuses. McKenna resolves to kill him, but Section 20 bursts in to rescue. Later at the Crib, Locke informs S20 that McKenna's team is planning to attack a NATO hub to gain intel for al-Zuhari's attack on a Western military base.
The team realizes too late that an IRA van is parked outside the British Embassy. The vehicle shoots a round of explosions into the building, and the team rushes to neutralize the two other vans parked around the city.
Disguised as a paramedic, McKenna heads into the damaged embassy building to reach a NATO access point located beneath the building. Locke captures her and demands the name of his son's killer, but before she can answer, she's killed by Leo Kamali. The next day, the team learns that the attack was successful: McKenna's team was able to clone a drive with NATO intelligence, and the stolen intel is being decrypted in Russia.