How does the author use foreshadowing in A Severed Head?

In Chapter Fifteen, Martin begins to unravel. The previous encounters with Honor have been unpleasant yet Martin sits down to have a drink with her. This behavior foreshadows coming events, both good and bad, between Honor and Martin. The incident with the Samurai sword is very symbolic. The cutting of the napkin represented Martin cutting ties with Antonia and Palmer as well as other areas of his life, perhaps even Georgie.