A Soviet submarine captain defects with his boat, and almost the entire book is two navies trying to work out what is happening from sonar contacts and inference.
Read in April 2013, long after I had worked through most of the others, which was a strange way round to meet the first one. It is leaner than everything that followed. No global cast, no parallel crises, one problem held for four hundred pages.
The best of them, and the shortest, which is not a coincidence.
