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...

In Chinese culture, live theater performances are attended by all classes of society. This short shows a performance of "The Rainbow Pass," a tale of a wife who challenges her husband's murderer to combat.