Stonebridge, Scott and the others sign up for another do-or-die mission after the daughter of Thailand's British ambassador is kidnapped.
Section 20 try to find the real culprits behind the embassy attack, as they attempt to gain information from gangster Ray McQueen.
Locke works out that his long-time friend's widow is working with the dangerous Yakuza and Office 39. Scott needs to protect his son after they find themselves under enemy fire.
Scott has a serious talk with his son while the rest of Section 20 form an uneasy alliance with a couple of CIA mercenaries as they go after Shiro and Mei Foster.
Scott and Stonebridge risk war by entering North Korea, in an attempt to destroy the stolen Vanadium.
Scott and Stonebridge make a major mistake and end up in the clutches of Li-Na. Locke has to decide whether to defy orders to get them out.
The battle with Li-Na is now in Europe, as Section 20 look for a way to get back on her trail. Locke ends up getting an unexpected chance to confront his nemesis.
The team find out that Li-Na is planning to mount a nuclear attack in Europe. Locke puts himself in the firing line after he neglects the mission in order to avenge his son's murder.
Locke takes Section 20 off the radar, as they defy Whitehall to travel to Geneva where he is convinced that Li-Na and Kwon are preparing to attack the United Nations HQ.
Scott and Stonebridge head out for a final showdown with Li-Na, in an effort to avenge Richmond’s death and save Locke’s career and their own lives before a bomb goes off in Europe.