Still haunted by the memory of a disastrous Special Forces mission which he led in 2003, John Porter is given an opportunity to redeem himself by returning to Iraq to rescue a kidnapped TV reporter.

After locating the terrorist safe house Katie is being held in, Porter is also taken prisoner, and Hugh Collinson and a team at Section 20 have to act quickly before it is too late.

Collinson sends Porter undercover to Zimbabwe on a mission to break a former British soldier who was involved in a political assassination out of a high-security Harare jail.

Porter and Masuku become the hunted as a bushman tracker leads the relentless Zimbabwean authorities after them, and Layla Thompson becomes increasingly aware of the tension that exists between Porter and Collinson.

When a hacker interferes with air support causing a British missile to hit American forces, Porter is assigned the mission to find the man responsible, a former guidance engineer who was dismissed from the army. However, Porter is kidnapped and taken to a Taliban camp.

Porter's life is in danger when he finds himself trapped in a rebels' base in Pakistan. When he manages to escape, he learns that Hugh Collinson, the man he blames for the fatal hostage extraction of 2003, has arrived in Afghanistan to meet him for a final showdown.

British sergeant Michael Stonebridge recruits help from Ex-Delta Force operative Damien Scott when Section 20 agent John Porter is kidnapped by a Pakistani terrorist. The two then uncover clues to a possible terrorist attack at a New Delhi hotel and race to foil it.

Scott and Stonebridge discover that the terrorists in the hotel are searching for Mahmood. Grant learns that Latif's real goal is to capture a Pakistani chemical scientist who worked with the weapons inspection team in Iraq in 2003.

Stonebridge, Scott, and Marshall stake out a trio of suspects in South Africa who might have some information about Latif. Ex-IRA leader, Daniel Connolly heists an armored truck in Cape Town.

At a remote facility outside Cape Town, Connolly closes in on his WMD prize, while Stonebridge and Scott are faced with dilemmas that could have far-reaching implications on their organization - and on the thread that connects them to Latif.

Stonebridge and Scott pose as aides for arms dealer Gerald Crawford to negotiate the release of hostage, Dr. Clare Somersby.

The first attempt to rescue Clare ends with Scott in the hospital and Stonebridge in pursuit with Crawford and Jacoub. Tahir takes Clare to a Janjaweed camp. Soldiers look for Scott at the hospital. Grant threatens Maggie about her story.

Stonebridge and Scott go to Kosovo to exchange a prisoner for kidnapped European Union officials.

Scott and Stonebridge are held captive with the four EU hostages in the wilderness of Kosovo. Hasani plans to sell Dana as a sex slave, and Allen, the double agent who has been providing information to Latif.

The boys are called away after MI5 team traced Latif to Chechen rebels country hideout, which turns out to be an abandoned vast Soviet area tunnel complex. They go in with support from Georgian commandos, which are eliminated by explosives. Latif escapes with some cahoots, who were screened for surgery. Some turn up in Budapest, where a world security summit is held, carrying the neuro-toxin and sophisticated bomb found in the tunnels. Damien also found indications of foul play since his Iraq set-up army booting.

Latif is finally in Section 20's clutches. The team frantically tries to discover the bombers' target and for that they need Latif to talk. Scott and Stonebridge go after the bombers. Latif's henchmen attack Section 20 command.

Damian Scott is sent to Mogadishu, Somalia to rescue British diplomats after they are kidnapped by warlord Huseyin Waabri. Meanwhile Michael Stonebridge adapts to his new career outside Section 20.

Scott learns that one of the hostages is a high-ranking military intelligence operative and that Waabri is planning to sell nuclear devices in South Africa.

Scott and Stonebridge track down a radical Islamic cleric in order to recover the nuclear devices, but are sidetracked by a CIA air strike and hostile locals.

Scott and Stonebridge prepare for an attack by Al Qaeda while holed up in an Algerian farmhouse with the nomad leader and the wounded courier. Meanwhile, back at headquarters, Dalton is called on the carpet for her relationship with the courier.

The trail of the missing nuclear triggers leads to Cape Town, South Africa, where kidnappers abduct the children of an expatriate munitions expert to force him to cooperate.

Stonebridge seeks revenge on Craig Hanson after he turns up in Cape Town, South Africa. Meanwhile, Scott reconnects with a Mossad agent who's been following their case, but with a different set of orders; Knox hustles Evans to a secret installation and explains how he intends to turn his country into a world power.

Knox extricates a political leader from a Zimbabwe prison, and the unit tries to catch up with the escapee by tracking his activist daughter.

Community unrest plagues South Africa and Zimbabwe following Lutulu's shooting. Stonebridge questions the shooter, while Scott, Lilian and Lutulu are on the run from assassins. Knox and his new ally make a new plan.

Knox plans on unloading nuclear bombs into politically unstable African nations, while Matlock reveals why he joined Knox.

In order to stop Knox, Scott comes to Bryant for assistance. Meanwhile Stonebridge has trouble focusing on the mission as he is bent on revenge. Section 20 get assistance from South African police to stop Knox's plot.

Enjoying a long-deserved vacation, Scott and Stonebridge are recalled after a fellow Section 20 member dies while pursuing the elusive terrorist al-Zuhari in Beirut. A new lead sends them into the remote jungles of Colombia in pursuit of a known associate of al-Zuhari’s and deep in territory controlled by a powerful drug cartel.

Out of options and hunted by the resourceful cartel, Section 20 goes for a longshot and attempts an assault in downtown Bogota, hoping to obtain intel on one of al-Zuhari’s key people. Meanwhile, Dalton looks for the source that exposed her team in Beirut, but discovers a surprising ally and a piece of al-Zuhari’s plan.

Although they are uncertain of others’ loyalties, the team must work with an asset in Beirut to get a lead on James Leatherby, a dangerous and unpredictable operative with ties to al-Zuhari.

Section 20 attempts a risky rescue for a potential new ally. Now veering close to the edge, but determined to find the truth, Dalton goes AWOL with a detainee.

While recovering from a shocking turn of events, Section 20 faces a different threat: a new enemy joining forces with an old one. Locke draws Kamali in closer to the team. Scott looks for an old friend, while Stonebridge gets closer to a new one.

Section 20 is torn between devoting their resources to the mission or saving one of their own. Stonebridge's health continues to affect him in the field. Al-Zuhari's network moves forward quickly, striking close. Kamali explains why yet another threat is emerging.

The team tracks stolen property to Russia, where Scott and Stonebridge continue their side careers as "outlaws." As Stonebridge's health continues to deteriorate, they discover new mysteries about a piece of Al-Zuhari's plan. Kamali worries that his cover identity may not hold.

Scott looks for an escape from Black Bear Prison, while Locke becomes suspicious of Kamali. The team races to locate Stonebridge, whose condition grows more dire when he encounters Al-Zuhari's plan firsthand. Continuing his vendetta, Ulyanov closes in on Scott and Stonebridge.

Scott and Stonebridge try to keep their promise to protect Ester; Richmond and Martinez follow an Al-Zuhari associate; the team sets out to stop an infiltrator before he reaches a populated area.

Scott and Stonebridge face a new pivotal player in Al-Zuhari's plan, and with an imminent attack looming, the team resorts to questionable measures, sparking conflict within the unit.

The daughter of Thailand's British ambassador is kidnapped, so Stonebridge, Scott and the rest of the team sign up for another do-or-die trying adventure.

Section 20 try to track down the real culprits behind the embassy attack, starting with getting information from gangster Ray McQueen.

Locke works out that his long-time friend is working with the dangerous Yakuza and Office 39. Scott needs protect his son after they find themselves enemy fire.

Scott has a serious talk with his son whilst 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 smuggle themselves into North Korea by posing as Russian rail workers and make a major mistake and fall into the clutches of North Korean agent Li-Na, leaving Locke having to defy orders to get them out.

Scott and Stonebridge's capture attracts worldwide media attention, prompting Whitehall to deny their existence, whilst ordering Locke to stand down.

The battle with Li-Na moves to Europe as Section 20 searches for a way to get back on her trail, while Locke gets an unexpected opportunity to confront his arch-enemy.

Section 20 discovers that Li-Na is planning to mount a nuclear attack in Europe, while Locke puts himself in the firing line when he neglects his mission in order to avenge the murder of his son.

Locke and his team go rogue once more as they defy Whitehall to travel to Geneva, where he is convinced Li-Na and Kwon are preparing to attack the United Nations HQ.

The action adventure reaches its explosive finale as the members of Section 20 try to thwart Li-Na's plot to bomb the United Nations HQ in Geneva.