John P. Marquand & John Betancourt 
Stopover: Tokyo [EPUB ebook] 

Marquand’s final novel featuring Mr. Moto, set in Japan shortly after the Korean War. Jack Rhyce is an American secret agent in Japan, hunting a Russian agent. He’s travelling with a female American agent: the two are posing as a couple. In Japan, they encounter Mr. Moto, who’s also after the Russian agent.