A new book is giving insight into the life of an MI5 agent, including some of the dangerous missions he was a part of. The memoir, titled Soldier Spy and written by a former spy under the pseudonym Tom Marcus, reveals the writer's history with Britain's domestic intelligence agency.

Released last week, the book had to be vetted by MI5 to ensure the contents would not risk a security breach, suggesting that the events the author has written about definitely did take place. However, Tom is keeping his real identity secret to avoid any possible reprisals.

While he isn't letting us know who he is, the book does give some information about his life – which was quoted exclusively in The Sun – including the fact that he spent his childhood in a northern city and he spent some time on the street when he was young.

He ended up joining the Army at 16, becoming the youngest person to complete the special operations selection, which is incredibly gruelling and meant he had to work undercover. Tom then met his wife – whose name has also been changed in the book for protection – when she joined as a Special Ops recruit. She was one of very few women who managed to pass the course.

Tom was approached by MI5 shortly after the 2005 London bomb attacks, as they were looking for someone who was "comfortable on the streets". This led to him undergoing more training, which included advanced driving and foot surveillance.

As part of the MI5, Tom would have to follow targets for weeks without giving himself away. He found that a great way to do this was to disguise himself as a homeless person so he could watch them from the streets.

Just before the London 2012 Olympics, Tom was part of the team that took down a four-man terror group based in Bradford, West Yorkshire. The group had intended to plant bombs at certain points throughout the country, but they were taken down following an operation that ran for almost a year.

Tom also reveals in the book that he has been in very real danger several times, including once when his cover was almost blown by a local gang.

The book definitely looks like it's going to be interesting, so are you going to give it a read?