Guthrie, Mycroft's secretary and his Watson, is accompanying Mycroft to a series of discrete negotiations with Japanese, intended to secure England's positions in Japanese-controlled waters.

But there are those on both sides who would like to see the talks come to naught, for reasons both political and radical. However, despite many setbacks, misunderstandings, and suspicious accidents, the agreement is near completion.

The night the papers are to be signed and sealed, a British diplomat whose opposition to the negotiations is no secret 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.