Although there may be a bias towards more up-market titles, the book sale at work contains all sorts. This looked like an airport thriller, but perhaps of a better sort, and I think that's how it turned out.
There must be no shortage of novels set in the second world war, and indeed, no shortage of real-life events on which to base them. This one takes its inspiration from the Venlo incident, in which British intelligence officers, following a false lead on a plot to depose Hitler, were abducted from the Netherlands by German security services. This is the point of departure into fiction; in the novel, the driver of the British car, who escapes, is Conrad de Lancey, another British officer drafted into the plot by virtue of his German connections whilst a student. So, one thread of the plot focuses on his dialog with a student friend now working in the Abwehr, committed to Germany but not to the Nazi regime; whilst another thread examines the role of the Duke of Windsor in Paris, inspecting the French defences, and reporting on them ... to whom? Meanwhile, political groupings in London are moving beneath the water.
The cleverness of the book is in showing a range of attitudes and motivations, all focused on ending the war, and most of them honourable. From time to time, reality is stretched, as one might expect; some of the characters are paper-thin, and some of the conspiracy reaches high levels of paranoia, but overall it just about hangs together. One feels there should be an inevitable conclusion, but the reader is definitely kept guessing.