1939's "Mr. Wong in Chinatown" was Monogram's third entry in their six picture detective series, its May shooting introducing a new character to the dynamic between Boris Karloff as James Lee Wong and Grant Withers as Capt. Bill Street, Marjorie Reynolds as Roberta 'Bobbie' Logan, blonde reporter and new wisecracking sweetheart of the increasingly downtrodden captain. Less complicated than its predecessors, it begins with Lotus Long's second series appearance, making a late night call upon Mr. Wong, who soon discovers her dead from a poisoned dart fired from a Chinese 'sleeve gun' like one he himself owns. Bobbie Logan identifies her as Lin Hwa, a princess who has spent the previous three weeks in San Francisco attempting to secure airplanes for her brother's fight against the Japanese. A dying clue was scribbled down before she expired, identifying 'Captain J,' of which two men made her acquaintance, the captain of the ship that brought her from China (William Royle), and the man whose Los Angeles company was negotiating to sell her the planes (George Lynn). A search of Lin Hwa's apartment reveals two faithful companions, Lilly Mae (Bessie Loo) and a mute dwarf (Angelo Rossitto), neither of whom are destined to live long, while Wong's inquiries with bank president Davidson (Huntley Gordon) ends up with a ride in a booby trapped taxi cab. Having learned that every penny deposited by the princess has been withdrawn through forged checks, the irate captains kidnap both Wong and Davidson to learn the whereabouts of the missing money, but the actual killer is tripped up by a little sleight of hand (this would be the last time seeing Karloff's Wong in his home). As obnoxious as reporters generally are in such films, it's a pleasant surprise to find Bobbie Logan better able to protect Mr. Wong than her police captain boyfriend, though their bickering only slows the picture to a crawl. Like first entry "Mr. Wong, Detective," this too would become a Charlie Chan remake for Monogram in 1947, "The Chinese Ring" not only marking the debut of 42 year old Roland Winters as Chan but also retaining the pretty reporter character in the person of Louise Currie, while the dwarf is rewritten as a Chinese boy. In for just one scene as an aged tong leader, Richard Loo previously played Karloff's lieutenant in "West of Shanghai," and would also feature in the next two entries (before filming the next series title, Karloff would complete "The Man They Could Not Hang" at Columbia and "Tower of London" at Universal).