Yoshitaka, who was about to leave his marriage and his wife, is poisoned by arsenic-laced coffee and dies. His wife, Ayane, is the logical suspect - except that she was hundreds of miles away when he was murdered. The lead detective, Tokyo Police Detective Kusanagi, is immediately smitten with her and refuses to believe that she could have had anything to do with the crime. His assistant, Kaoru Utsumi, however, is convinced Ayane is guilty. While Utsumi's instincts tell her one thing, the facts of the case are another matter. So she does what her boss has done for years when stymied - she calls upon Professor Manabu Yukawa. But even the brilliant mind of Dr. Yukawa has trouble with this one, and he must somehow find a way to solve an impossible murder and capture a very real, very deadly murderer.