Paterson Guthrie, Mycroft Holmes's secretary, is accompanying his employer to secret negotiations with the Japanese, intended to secure England's position in Japanese-controlled waters. But many highly placed Englishmen do not wish to ally themselves with a people they consider inferior, and the Japanese are wary of close ties with a society they find increasingly hostile. And why is the flirtations Miss Gatsby, sometime spy, sometime assassin, lurking around the embassy--is she after information, or Guthrie?

Despite misunderstandings and suspicious "accidents," the agreement is near completion. But the night the papers are to be signed and sealed, a British diplomat firmly opposed to the negotiations is found dead with a Japanese dagger in his back. Mycroft and Guthrie must solve his murder, expose the agitators behind it, and see to the finalization of the agreement--without finding themselves on the wrong end of the knife.