![](https://image.tmdb.org/t/p/original/j13lQyshMlOVGiiH8jqzjiyg5IT.jpg)
![](https://image.tmdb.org/t/p/w200/eG3bPkQBKmvRzAz3PO8FE5tB39p.jpg)
A pretty Chinese woman, seeking help from San Francisco detective James Lee Wong, is killed by a poisoned dart in his front hall, having time only to scrawl "Captain J" on a sheet of paper. She proves to be Princess Lin Hwa, on a secret military mission for Chinese forces fighting the Japanese invasion. Mr. Wong finds two captains with the intial J in the case, neither being quite what he seems; there's fog on the waterfront and someone still has that poison-dart gun...