This novel is set during World War II in a quiet suburb. One day schoolboy Keith announces to his friend Stephen that his mother is a German spy, so they set about following her to try and uncover her secret. However, as the adult Stephen revisits his old home he begins to confront the reality of what was really happening. The title poses the question about who the spies really are – Keith´s mother or the boys?
The first part of the book is really engaging and draws you into the story. The boys’ conclusions when reading Keith´s mother´s diary about the mysterious marks that she puts in her diary every 28 days and how they presume they relate to meeting a mysterious German are extremely funny. Frayn reminds you of your own childhood; hiding in dens and smoking old discarded cigarette butts.
Unfortunately life got in the way and I stopped reading this for about a week, and found that I had lost my involvement in the plot and in the second half I started to find the story a little repetitive mainly because Frayn intends that the reader has worked out what has happened before Stephen does. There are a few surprise revelations that are thrown in the end which were interesting, it was a thought-provoking book.