Sordid crime or a settling of scores? The British Secret Service has just learned that North Korean authorities wonder about the murder--with no apparent motive--of a British citizen who was passing through their capital. The news is all the more embarrassing because the victim is none other than Sir Harold Wilberforce Clifton, one of Her Majesty's most famous agents! The colonel had been given a mission to bring back to Great Britain the nephew of a highly placed personality, the young man having been indoctrinated by the followers of a sect named 'the Black Moon.'