The Russians are launching a nuclear strike on London. The only person who can help the team at this desperate hour is the traitor amongst them. With the Russians hunting them down, the team usher their traitor through London in a desperate bid to reach the codes and the bomb in time.

Harry is imprisoned and accused by MI5 of being the Russian mole. Lucas goes to Moscow to get to the bottom of Harry's arrest.

A teenage boy accidentally stumbles upon a government conspiracy and is instantly absorbed into the world of MI5 for protection.

Ros goes undercover in the City to flush out a dangerous international financier who wants to bankrupt Britain.

The team is stunned to discover that Al Qaeda's number three wants to negotiate. It's a risk, but Harry and the team have to take this chance for peace.

Lucas reveals that the Russians interrogated him about Operation Sugar Horse, the most secret ongoing spy operation MI5 ever had.

Harry vows revenge by taking down the head of Russia's intelligence service in Britain with the help of Lucas North.

An Al Qaeda cell kidnap a soldier and demand that Remembrance Sunday be cancelled as it is an affront to all dead Muslim soldiers.