The missions of MI-5, the UK's domestic intelligence organization.
Cast:Peter Firth , Hugh Simon , Nicola Walker , Rupert Penry-Jones , Miranda Raison , Hermione Norris , Rory MacGregor , David Oyelowo , Richard Armitage , Raza Jaffrey , Keeley Hawes , Shauna Macdonald , Matthew Macfadyen , Shazad Latif , Gemma Jones , Robert Glenister , Anna Chancellor , James Dicker
An abortion doctor is executed by an American pro-life terrorist; Mary Kane. An informant reveals that this is just the tip of the iceberg as Mary has 20 more bombs and plans on using them.
The team uncover connections between racist ring-leaders, politicians and mass killings of immigrants, and are forced to go undercover in order to investigate.
Zoe is caught in the middle of a siege on the Turkish embassy, while Tessa is stunned and confused when she sees a man from her past.
Ellie questions whether she can cope with dating a spy, and Zoe discovers Tessa is up to something. Meanwhile, Tom's mentor is working undercover at an anti-Bush rally when his methods start to appear dangerously unconventional.
Disgraced MP Hampton Wilder's memoirs could create a scandal big enough to bring down the government.
Patrick McCann, the leader of an Irish splinter group, walks into a safe house armed with a grenade, and demands to speak to someone at MI5 about some crucial information he has on a Middle-Eastern terrorist group called Asabiyah.
The team at MI-5 believe that a revenge campaign by a Bosnian war criminal may be underway.
Police uncover a large scale fraud at a mosque in Birmingham, where one of the leaders is believed to be redirecting charitable funds into bank accounts for his own use, and where suicide bombers are being trained.
A hacker gains access to MI5's central computer, leaving agents stranded in danger zones across the world. Prime suspect is a school teacher who has links to the left-wing extremists.
After stealing a large amount of money from a bank a man is found Crucified on the moors. The treasury call in the team to investigate but when Harry decides to take the mission further, Danny's life is put in danger.
The team believe they are undergoing an Extreme Emergency Response Initiative Exercise, a practise run for a national emergency - until evidence indicates that the threat of a VX nerve gas attack in Parliament Square is real.
When the American president makes an unexpected visit to the UK, Tom is thrown together with a CIA agent named Christine, and it soon appears there's more to their relationship than just work.
The French Intelligence Service wants to work in partnership with MI5 to catch an arms expert they suspect of selling Eurofighter technology to the highest bidder.
As Britain is hit by a wave of strikes, Tom is sent undercover to investigate a decorated British Army Major suspected of plotting a mutiny. He soon discovers a plan involving turning stolen radioactive waste into a dirty bomb.
MI5 come up against the Chala Cartel, Colombia's biggest drug traffickers, when eight customs and excise officers are murdered. Surveillance reveals a link between the cartel and one of Britain's leading oil companies.
Tom ignores Harry's demands to end his relationship with CIA officer Christine Dale. Christine hands Tom a secure communication which she has accidentally received from high up in the CIA.
The team must find out if Tom is really a traitor, and whether he shot the Chief of the Defence Staff.
Sleeper agent Fred Roberts is activated in order to infiltrate a terrorist group.
When the team investigate the attempted assassination of a famous novelist, they discover he may not have been the target after all.
A diplomat is killed while attending the latest round of Middle East talks, and MI5 suspect a link with a shadowy group known as the November Committee.
Whilst on the trail of a rogue scientist, Zoe is accused of letting her relationship with Will interfere with her work.
MI5 are alarmed when they discover a group is hacking into computer systems across the country tampering with ingredients in painkillers making everyday drugs lethal, wiping bank balances, disrupting traffic lights systems.
The baby son of rock star and popular icon Riff is kidnapped during a party and MI-5 are drawn into the high-profile investigation.
MI-5's suspicions are aroused when a known mercenary, Robert Morgan, is seen visiting a top-secret disused Soviet arms dump.
When Danny and Fiona are taken hostage, it sets off a deadly chain of events for the team at MI-5.
When an American extremist group sets off a bomb in London, promising more attacks if their demands aren't met, the team must act fast to prevent any more casualties.
Harry and Juliet are in a power struggle, while Adam and Zaf continue their fight against the American extremist group Shining Dawn.
When MP William Sampson announces he is crossing the floor to join the far-right party The British Way, it is up to Adam to infiltrate and destroy the party from the inside.
Adam and Zaf are sent to Istanbul where they attempt to move a terrorist away from his extremist ideals.
Harry mourns the suicide of a retired MI-5 officer until a journalist informs Harry the officer was murdered because he'd been about to sell his autobiography and expose a lifetime of service secrets.
An attack is orchestrated by an Algerian terrorist in prison, and the decision is made to free him in order to gain more information about his plans.
Fiona goes undercover as a PR executive in order to rendezvous with the Syrian Foreign Minister, Riyad Barzali, who has indicated he wants contact with MI-5, but can't shake the constant surveillance of his secret service.
After the death of Fiona, Adam is tasked with the investigation of Oleg Korsakov, a multi-millionaire Russian investor, who the government see as the saviour of the NHS. Is his offer of financial intervention too good to be true?
As Britain teeters on the brink of war with Iran, Harry prevents an unofficial extradition of a terrorism suspect by the CIA, thinking he poses no serious threat to national security.
Ruth is visited by his partner Angela, an ex-MI5 officer, who asks Ruth for help in proving that MI5 killed Lady Diana. When Ruth refuses to help her, Angela takes matters into her own hands, visiting the Grid with a deadly proposition.
Terrorists carry out several devastating attacks on British targets which lead to panic and new extreme legal measures being rushed through Parliament, but is there more to this than meets the eye?
While Juliet has to come to terms with her injury, MI5 begin to unravel a conspiracy which sees an elite group trying to take control of Britain. They eventually see that this goes much further than anyone expects.
Intelligence suggests that a thermobaric bomb is being sold to terrorists. Using Zaf as an insider, section D look to intercept the bomb before it does irreparable damage to London, but things don't go exactly to plan.
During a world conference which could signal the end of poverty in Africa, MI5 uncover two conspiracies which threaten an individual life and world relations. Is anyone using the conference for its intended purpose?
Ruth is witness to a stranger killing himself in a subway station and is led to a series of clues which will change her world forever.
Ros goes undercover with the Saudi royal family in order to investigate a Saudi prince who may have ties to al-Qaeda.
As Ros is held hostage at the Saudi Trade Centre, the team at MI5 must face the disturbing fact that the terrorists may not be Al-Qaeda after all.
Harry Pearce is less than pleased when he learns that MI-5 video surveillance of a suspected terrorist, Khalid Mansour, has been ruled inadmissible and that Mansour will be set free. On the steps of the courthouse moments after being released however, Mansour is shot and killed with the assassin, Daniel Ellis, promptly committing suicide. After a second suicide attack claims the life of a radical Muslim cleric, an anti-Islamic organization known as the Sons of Phineas claim responsibility. Though they have no information on the organization, MI-5 focuses on Steven Paynton, who runs a homeless shelter where both men lived before their attacks. They set up a sting to try and get Paynton to give them information on others he may have recruited to his cause. With racial tensions rising across Britain, Adam goes undercover to rope him in but when his young son disappears, he fears his job may cost him what is left of his family.
When MI5 are tasked with protecting a high profile witness in a war crimes trial, a former traitor reappears and asks Adam to trust him again.
Environmental terrorists take control of the Thames barrier just as a major storm surge threatens to flood the London area. They demand that the British government publish a secret document entitled Aftermath but MI-5 can't find it. It's apparent that the Deputy Prime Minster, the PM is away, knows far more than she is saying. Adam meanwhile continues to struggle with post-traumatic stress syndrome. When he enters the facility to negotiate with the terrorists, he suffers an attack and is unable to function. It's left to Ros to find a way in and convince their captors that they've won and the document will be published.
The team race to stop a rogue member of Iranian intelligence who may be planning to unleash a bio-weapon in the UK.
A plague-like virus is unleashed in London. Facing the prospect of half a million dead, Harry orders the team to take extreme measures in an attempt to obtain the antidote from allies who may be keeping it a secret.
The team investigates a suspicious plane crash near an American airbase in the UK and uncover a link to the mysterious "Copenhagen". Ros's captors subject her to mental torture and reveal some disturbing news about Zaf.
Abdul Kharami is a suspected terrorist who is under constant surveillance but manages to evade his watchers just as MI-5 receives reliable information that he may be ready to stage an attack. Kharami specializes US targets and given the Americans set them up with the Tehran explosion, Ros for one thinks they should just ignore him. Harry Pearce thinks otherwise and brings his American counterpart, Bob Hogan, up to date. He also authorizes the launch of Operation Zebra, MI-5's plan to infiltrate the CIA. When Kharami's plan is traced to the Iranian Special Consul, Adam uses his special contact there to find out what is going on but it goes horribly wrong. As Ros learns from her Yalta contacts, Kharami's intentions - and his target - aren't are as straightforward as MI-5 may have thought.
On his way to intercept a Russian arms dealer planning to sell nuclear weapons blueprints to Iran, Adam, in self defense, kills a mugger who later turns out to be a journalist. Adam has a last fateful encounter with Ana.
Adam and Ros board an airplane to identify a courier carrying nuclear weapons technology to Iran. Jo and Malcolm race to prevent the poisoning of London's water supply which Iran has threatened if the courier does not reach his destination.
Aware that Iran now has full nuclear capability, Harry and Bob convince Bakhshi go on live television to announce that Iran has ended its uranium enrichment program, but armed activists learn the truth and hijack the broadcast.
Ros's relationship with Yalta is revealed. With limited options, she turns herself in, but convinces Harry that his best option is to send her back out as a double agent.
With the team on suspension in the aftermath of the Ros Myers affair, a former IRA operative and one time associate of Connie targets section D for extermination.
War with Iran finally averted, the team learn that a London school will be the target of hardliners resisting the new peace. Simultaneously they discover that their lost colleague, Zaf, was grotesquely tortured and killed by a group of mercenaries. When Jo is snatched by the group, Adam resists calls to stay focused on the school threat; the war has become personal and he must find Jo at all costs.
The team step in when a British soldier is kidnapped by al-Qaeda. Meanwhile, an old protégé of Harry's returns to the fold after eight years in a Russian prison - but whose side is he really on?
Convinced that his Russian counterpart in London, Arkady Katchimov, is behind the Al Qaeda bombing that killed Adam Carter, Harry Pearce launches an unauthorized investigation. Their task is to find a non-diplomatic source who would provide then with information on Katchimov's activities. Meanwhile, listeners capture an electronic burst leading them to believe there may be an unidentified Russian submarine in British waters. With Ros Myers now the head of the team, they focus on Alexander Beletsky, a Russian who has a relationship with Katchimov. They conclude that the Russians may be looking to tap undersea communications cables and launch a denial of service attack, thereby disabling the Internet throughout Britain. Lucas North is keen to get back to work but Harry insists that Lucas go through the entire re-integration process before he does so. A good decision given that it appears that North may in fact be working for the Russians.
When a Pakistani agent informs them that there is an Al Qaeda cell planning an attack in London, MI-5 go into action. They already have an agent in place in the terrorist cell which is led by Nadif Abdelrashid. When what is supposed to be dry run turns out to be the real thing, MI-5 track four bombers as they walk through the city to what is their final destination. One by one, MI-5 try to take each of them down before the bombs explode but they aren't entirely successful. Lucas North meanwhile has a flashback to being tortured by his Russian jailers and recalls one of the interrogators asking about an operation known as Sugar Horse. For Harry Pearce alarms bells go off as the operation was one of the most guarded secrets and known only to a very few. He is convinced there is a Russian mole in the senior levels of the intelligence community and turns to Bernard Qualtrough, a retired spy catcher, to help him ferret out the turncoat.
MI-5 is approached by Mohammed Khordad, the number 3 man in Al Qaeda, for a meeting. Under normal circumstances, they wouldn't even think of meeting the leader of a terrorist group but Harry Pearce is convinced that they should look at any opportunity to reduce the threat of attacks. Khordad is keeping his cards close to his chest and insists that they have to trust one another before they can deal. He tells Harry that a bomb will go off at 3 pm that afternoon unless the Home Secretary publicly absolves two suspected terrorists of any wrongdoing. If he can do that, he will then have more important information for him. As the MI-5 team try find the location of the bomb and Harry tries to convince the Home Secretary of the necessity of making a statement, they also have to deal with another problem: the CIA, which also has a interest in Khordad.
Ros goes undercover to flush out a dangerous international financier who wants to bankrupt Britain. Suddenly it's not just the economy, but also Ros's life, that is at risk.
A teenage boy accidentally stumbles upon a government conspiracy and is instantly absorbed into the world of MI5, ending up on the run.
Sugar Horse is revealed to be a network of sleeper agents in Russia. They are there for use only in the direst of circumstances. Just as the West's relations are on the brink - there is much sabre-rattling when the US announces its plans to install its missile shield in former Eastern European countries - two Sugar Horse agents are apparently murdered. All of the evidence points to Harry Pearce who is arrested and is forced to undergo severe questioning. Lucas North travels to Moscow to see what he can learn. A member of the MI-5 team is revealed as a Russian mole and is now desperate to be extracted after killing another member of the team.
With the Russian mole inside MI-5 now in custody, the team tries to decipher the information Lucas North obtained in Moscow. It is apparent that the Russian intelligence service had their own equivalent to the British Sugar Horse network and have sleeper agents across Britain and throughout the various security agencies. Information from the mole indicates that a thermonuclear device will be exploded in central London and offers to reveal the identity of all sleeper agents in the UK if they agree to provide protection and a relocation package. The Russians have issued instructions to kill Harry Pearce and all of the members of Section D so getting to the mole's information will be difficult. Harry decides to meet his Russian counterpart to ensure he knows that they will all die if they don't work together to stop the bombing.
Harry is still missing and there is one question on everyone's mind: is he dead, or alive?
When an industrial accident put a liquid natural gas plant out of commission for six months, the UK must quickly arrange for an alternate source of supply or face an energy crisis that will cripple British industry and the economy, to say nothing of its citizens' quality of life. The government is reluctant to deal with the Russians who will inevitably attach other demands to any sale, let alone give them a good price. Their only choice is to deal with Tazbekistan, a country that has recently undergone a change of government through a coup and is known for its abuse of civil rights and the use of torture on its dissidents. MI-5 is tasked to gather whatever intelligence it can about their negotiators and to also ensure that they and the Russians not seek revenge on each other in something that is akin to a blood feud. In the midst of all this the CIA, in the form Lucas North's lover Sarah Caulfield, tell MI-5 the US doesn't want the UK to make a deal with the Tazbeks and seem to be prepared to manipulate the situation to their advantage. Meanwhile, the Home Secretary tells Harry of information he has received in confidence from an American contact about a secret meeting in Switzerland that may have global repercussions.
A secret meeting of powerful tycoons is stormed by armed terrorists and eight of the world's richest men are taken captive.
When Lucas's former torturer Darshavin turns up with intelligence about a bomb in London, he must confront his demons for the sake of the nation.
When two CIA agents are found dead, Ros puts herself in the firing line in order to expose the killer.
Section D must recover over £1 billion from one of the world's most impenetrable banks before Britain plunges into a financial depression.
Section D must race against time to find out where and when a group of Hindu nationalists are planning an attack on the Muslim community.
When Pakistan seizes an Indian submarine that has strayed into its territorial waters, the world is on the brink of a war between two nuclear powers. The Prime Minister invites both parties to London for talks to calm everyone and avert a crisis but there are those who would seek to ensure the talks fail. Sarah Caulfield is a member of the conspiracy, known as Nightingale, and they are bent on starting a nuclear war. When a friendly Chinese diplomat tries to give them information about a possible attack on the peace talks, he is assassinated. MI-5 is convinced that they will cause an incident at the peace conference to push India or Pakistan over the edge.
Reeling after the explosion at the hotel, Section D are left considering the sacrifices they make as spies, but they are soon back in action.
The pressure is on for Beth when she goes undercover for MI5 for the first time, and is tasked with protecting a influential oil baron.
Section D are forced to welcome an FSB Officer onto the Grid to help track down Aibek, a rogue nationalist from the ex-Soviet State of Azakstan.
When a highly-skilled trio of Chinese agents arrive in London for 48 hours only, the team must find out why they are here.
Beth and Dimitri go undercover as Home Office representatives in order to protect the American president who is in London for top secret peace talks.
Relations between the CIA and MI5 are stretched after an American drone is hacked in Afghanistan whilst in British care, leading to the loss of American lives.
Lucas North's secret past is revealed as Vaughan raises the stakes in his efforts to get the "Albany" file. Ruth's life is in danger when she follows up a council worker's report of a "dead drop" in a park.
The team face their toughest challenge ever: tracking down Lucas North, their Section Chief, friend and one of the best agents MI5 has ever had.
Ilya Gavrik, Russia's foreign ambassador, Harry's opposite number in the KGB for much of the 80s, is in London to negotiate a groundbreaking deal between Russia and UK.
A laptop containing classified information is stolen from Calum when he is attacked during a routine exercise for MI6.
MI5 receive information that a highly dangerous anarchist has secretly entered the country.
Two former inmates released from prison are set to launch an attack somewhere in London.
Harry kidnaps his old Cold War colleague after new evidence of Jim Coaver's involvement in the attacks on MI5 surfaces.
Harry is handed over to the CIA ready for deportation, but when new evidence surfaces, his team break Harry out of custody.
