This is a very British murder mystery, written in 1969. I sometimes had a hard time understanding the lingo, but overall, not bad.
Two old English war heroes (brothers) have turned their estate into a Disney-esque Old England theme park, complete with private zoo and a man-eating lion. When a servant hangs himself, close-to-retirement inspector Pibble from Scotland Yard is called in, rather than the local police. It turns out that the suicide is not really a suicide and that one of the old brothers is missing, too!