In 1993, the IRA member Collette is arrested in the London tube after leaving a bomb in the facility. MI-5 Agent Mac offers a deal to Collette to become an informer. She accepts the agreement to protect her son and in return Mac offers a new identity to her after a period working for the MI-5. Soon Mac learns that his superior Kate Fletcher is using Collette to protect her mole inside the Irish organization. Mac tries to find the identity of the informer and protect Collette.

Keith Lemon ( ) is preparing to take his invention, the securipole, which he has been attempting to lift off the ground for twenty years, to a business convention in London. Meanwhile, his girlfriend Rosie (Laura Aikman) has discovered that she is pregnant, but due to Keith being away, instead confides in his best friend, Dougie (Kevin Bishop). At the convention, the securipole fails to attract any big investor attention, and back at home, an order of 1,000,000 securipoles arrives, much to Rosie and Dougie's dismay. Realising that his invention may never be successful, and that he now owes Evil Steve (Leigh Francis) a ton of money for the securipoles, Lemon decides to stay in London, and takes the advice of fellow businessman Kushvinder (Harish Patel), and accepts the gift of a new style mobile phone that Kushvinder has invented. Attempting to turn the gift into his next money-making scheme, Lemon accepts an offer to appear on David Hasselhoff's prime time television chat ...