London, 1956. A young woman has been found dead in a hotel in King's Cross. Broke her neck falling down stairs, the death certificate says. But Fleet Street journalist Gerry Blackstone thinks there's more to it than meets the eye. Scotland Yard's not interested in accidental deaths - if that's what this is. But maybe he can convince Special Branch's DCI Jack McGovern to investigate. Fortunately for Blackstone, McGovern needs his help. The new Superintendent wants to sweep out corrupt officers, and McGovern's his broom. If Blackstone can keep news of the investigation out of the press, McGovern stands a chance of finding the bent cop. Meanwhile, Oxford is filling with Hungarian emigres fleeing the failed revolution. With the memories of Burgess and Maclean's defection still raw, Special Branch is concerned that there could be Soviet spies among the genuine refugees and wants McGovern on-hand to keep an eye out. As McGovern carries out his casework in Oxford and Blackstone investigates behind the scenes in London, clues start to emerge that, somehow, this might all be linked. The deeper they look, the more unrelated characters with shady pasts start to complicate the picture: the well-to-do madam, the Classics Professor, the East London crime boss, the Oxford doctoral student, the fiery Hungarian immigrant, the government minister ... does it all lead back to the dead girl in King's Cross? Or is there something even more sinister going on?