Tense drama series about the different challenges faced by the British Security Service as they work against the clock to safeguard the nation. The title is a popular colloquialism for spies, and the series follows the work of a group of MI5 officers based at the service's Thames House headquarters, in a highly secure suite of offices known as The Grid.
Written by Sophie and last updated on nov 28, 2022.
PS: The following content contains spoilers!
PPS: I will admit that parts of this page was written with the help of AI - it makes my work so much easier to not start from a blank page!
MI5 investigate the assassination of a Muslim cleric outside the high court, and uncover a radicalised Christian who is determined to incite a religious war.
The episode was rated 7.68 from 76 votes.
Zaf goes deep undercover to infiltrate an Al Qaeda cell that is planning an attack on the UK. When Adam learns that the terrorists are on a suicide mission he tries to prevent them from reaching their target, but events soon spiral out of control.
The episode was rated 7.70 from 86 votes.
MI5 has foiled an attempt to murder the Home Secretary, but the plotters use the new emergency powers to imprison Harry. The team must try to frustrate the coup before Harry is executed.
The episode was rated 7.74 from 94 votes.
Adam and Zaf try to find a group of terrorists who have infiltrated Britain. Ros oversees a visit by a delegation of Saudi princes offering a guaranteed oil supply in exchange for nuclear expertise, but the Saudi Trade Centre is attacked by terrorists.
The episode was rated 7.80 from 85 votes.
The government publishes its report on the investigation into death of seven terrorist suspects in a fire at a prison. Harry suspects a cover up, then discovers that one of his team has been implicated.
The episode was rated 7.83 from 86 votes.
MI-5 is put in charge of protecting Niko Grecic, the former right-hand of Tezlia, a Serbian who is put on trial for war crimes. They know that Richard Dempsey, a former MI-6 agent who turned on them, is looking for Grecic to kill him before he can testify. Adam, Jo and Zafar must protect Grecic at all costs.
The episode was rated 7.88 from 67 votes.
An environmental terrorist group is threatening to flood London if the government does not make a secret document public.
The episode was rated 7.89 from 80 votes.
Posted undercover at the World Trade Summit for Africa, the team discovers an assassination plot. Initially determined to put their lives on the line to prevent the murder, they are faced with a moral dilemma on discovering the motivate behind the plot.
The episode was rated 7.94 from 83 votes.
The terrorists start to execute hostages in pursuit of their demand for the release of Al Qaeda prisoners held in Saudi Arabia, but suspicion arises as to the true identity of the terrorists.
The episode was rated 8.03 from 80 votes.
The government introduces draconian emergency measures in response to a series of terrorist attacks. MI5 fear that influential establishment figures are behind the attacks and may be planning a coup.
The episode was rated 8.07 from 105 votes.
