This novel is the third in a series featuring the Cambridge history professor Tom Wilde, the first two being Corpus (reviewed in HNR 80) and Nucleus (reviewed in HNR 83). Clements has also written a series set in Elizabethan England which is also recommended. The novels do not need to be read in order, but to be quite honest, you should not deprive yourself of that pleasure.
Wilde is on holiday in France in 1939 and inadvertently becomes enmeshed in the rescue of a former student, Marcus Marfield, from a concentration camp. Blessed with good looks and the voice of an angel, Marfield disappeared two years before after having gone to fight for the International Brigade in the Spanish Civil War. All is not as it seems, however, and Wilde becomes key in puzzling out hidden loyalties, dark secrets and political shenanigans.
There are many plot layers, such as the sinking of the liner Athenia in the Atlantic, the visit of Joe Kennedy to Britain, and a mysterious Russian woman who seems central to many of the events. The story is satisfying and keeps the pages turning quickly. Thoroughly enjoyable story-telling, reminiscent in some ways of The 39 Steps.