Keenness For Discord

Poul Anderson, The Man Who Counts, see here.

Van Rijn and his companions are captives of divided Diomedeans although van Rijn spots the divisions before Wace does:

"Wace thought that van Rijn's out-size nose must have an abnormal keenness for discord. Only now did he himself sense the tension on which his boss had obviously been counting." (VII, p. 376)

Then, even when Wace has been told that van Rijn is faking his ignorance of the local language:

"...he found it hard to believe that so ludicrous an accent and grammar were faked.
"And why?" (p. 377)

Here, Wace is being unforgivably obtuse. There are obvious advantages in seeming not to understand local speech. Van Rijn has learned of Fleet factions through his ears, not through his nose.