Detective incognito

Blurb

The Black Mountain is a Nero Wolfe detective novel by Rex Stout, first published by the Viking Press in 1954. The story was also collected in the omnibus volume Three Trumps.
This book and the pre-war novel Over My Dead Body both involve international intrigue over Montenegro, but under very different circumstances, first concerning Nazi designs on the Balkans, and later in the context of Tito's Yugoslavia.