As I've said couple times before, I've been reading British Hank Jason novels lately. This is a good one, one written presumably by Stephen Frances, who was a Communist (!)and took part in the Spanish Civil War. The original title is "Way Out Wanton" which has nothing to do with the story that focuses around Hank Jason, crime reporter of a Chicago newspaper, in British Guyana trying to find a diamond smuggler. Rather strikingly for a British paperback series this is written in present tense. It's a tough and quite cynical adventure novel, with some reminiscence of Conrad's "Heart of Darkness" when Jason sails up the river in the middle of jungles. Perhaps the best of Hank Jasons I've read. Some have been appallingly bad.

The illustration in the Finnish cover is by Robert McGinnis, snatched from another book. The title means "The Exciting Glitter" or something to that effect. The cover also says: "Diamonds excite everyone - some even to death!"