With Tom's family trapped in his house with a bomb, and nothing Tom or the other spooks can do but watch on. There is a huge explosion and the credits begin. However, there is no time to focus on these events as a Serbian warlord has been seen entering the UK vowing revenge for the death of his sons in a NATO bombing raid

A fellow agent informs Tom that young boys and men from a mosque in Birmingham are being trained as suicide bombers. They need an undercover spook, but who should or can go?

MI5's mainframe has been hacked into. But Tom and his team think they have found a lead in the form of an I.T

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

Tom's skills as leader are tested to their extremes when they take part in an Extreme Emergency Response Initiative Exercise (EERIE) to test their response to nuclear, chemical or biological act in central London, but when the power in the grid is cut and Harry starts to feel ill, they soon begin to suspect it's for real

The president of the USA makes an unexpected stop in London. Tom and his team are forced to work with the CIA. A power struggle between the two secret organizations begins, but will they stop fighting before a terrible mistake is made? And will Tom ex-girlfriend leave well alone or will she have to be taught a lesson?

A French scientist has gone renegade and taken a top secret weapon called Firestorm with him, which he is threatening to sell to the highest bidder. Now he has ended up in the UK, and MI5 is forced to work with French Intelligence. But the British want the technology

A new series of strikes prompted by the unions has the team worried. And when news of a 'strike' by the army arise, Tom is sent undercover to investigate. Meanwhile Zoe takes charge back at the Grid, and is tasked with moving spent uranium cells across the country after rail strikes prevent it taking it's usual route

Tom is undercover with Customs, but when he goes off to phone in, the rest of the crew are murdered. A Colombian drugs cartel are suspected. Zoe and Tom are sent undercover to 'turn' the girlfriend of the head of the cartel

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. It says that an American assassin has come to the UK for a hit and that the CIA are going to take him out, without informing Five or any of the security services