Arthur Rowe, a retired journalist, is the unlikely winner of a cake, the weight of which he correctly guessed during a charity fête patronized by The Free Mothers. For Rowe, the fête should have been an innocent trip back to childhood and innocence, a welcome chance to escape the terror of the Blitz and to forget twenty years of his past as a murderer. Instead he becomes a haunted man because he possesses a cake which was destined for somebody else. It turns out that the cake contains some poison - hyoscine - which nearly kills an innocent man called Poole. Then Rowe is involved in a séance with Mrs Bellairs, a fortune teller, and several other people during which a man called Cost is killed with Rowe's own knife. He manages to escape with the help of Willi Hilfe, an Austrian refugee. Next Rowe is accosted by a man called Fullove who specialises in eighteenth century landscape gardening books and who asks Rowe to help him carry his heavy suitcase to the Regal Court and to leave it there in the room of a certain Travers. A page guides Rowe to Mr Travers's room where Anna, Willi Hilfe's sister, is waiting. Soon after that, Rowe and Anna open the suitcase which contains no books but a bomb which goes off...
At this stage - the middle of the novel - the plot does not seem to make much sense but in the second part Mr Greene carefully assembles the pieces of the jigsaw so that by the end of the narrative the reader has a clear picture of the mystery. Reading the novel one realizes that war is like a bad dream in which familiar people appear in terrible and unlikely disguises and that nobody is to be trusted. That is the Ministry of Fear, the general atmosphere spread by the enemy so that one can't depend on a single soul. And then there is that other Ministry of Fear to which all who love belong since if one loves, one fears at the same time.