In 2010, Kate Wilson received a phonecall. It was a friend, telling her that her ex-boyfriend Mark was not all he seemed. In fact, he had never existed. The man Kate knew as Mark Stone, as a friend she had loved, slept with and lived with for two years, was in fact an undercover police officer called Mark Kennedy, sent by the state to spy on the environmental campaigns of which Kate was a member. Everything he had told her was a lie. And as the story unfolded, it became clear that Kate was not the only woman to have been deceived into a relationship with a member of the British police. Here Kate talks about her experiences and some of the issues which will need to be addressed by the Undercover Policing Inquiry.