A beautiful Chinese woman visits Mr. Wong, Boris Karloff late at night, but she is murdered before she can reveal why she came to seek his help. The dead woman is soon identified as Princess Lin Hwa, Lotus Long the sister of a powerful Chinese general, and she dies from a poisoned dart fired from a Chinese "sleeve gun." This brutal opening sets the tone for a case that blends personal danger with political intrigue, and it pulls Mr. Wong into a web of secrets that stretch beyond the immediate crime.
As with some of his previous investigations, Wong receives crucial information from the leader of a formidable tong, a Chinese secret society. The tong head explains that the princess had come to the United States with nearly $1 million, intending to arrange a covert purchase of airplanes that would be smuggled back to China. This revelation widens the scope of the mystery from a single murder to a possible international scheme, and it casts the princess’s money in a suspicious light that raises more questions than answers.
Following this lead, Wong learns that every penny the princess deposited in a local bank has vanished—withdrawn in a pattern that smells of forgery, with the signatures on most checks forged. The financial crime compounds the danger, and Wong suddenly finds himself a target for a killer who will stop at nothing to keep the truth hidden. Amid the peril, a blonde, energetic newspaper reporter steps into the investigation, offering wit, speed, and resilience to match Wong’s methodical approach, and together they begin to assemble the pieces of a plot that seems almost too large to grasp.
The central question cuts to the heart of the case: were the princess’s enemies acting to derail a plan to ship airplanes to China, or was the entire operation a carefully crafted deception with no planes at all? Wong’s relentless pursuit of evidence takes him from the ship on which the princess traveled to the offices of the aviation company and the bank where she kept her money. His conversations with the ship’s captain, the plane company owner, and the bank president gradually illuminate the layers of motive, trust, and betrayal, allowing him to draw a clear line to the killer.
In the end, the killer’s identity is uncovered through careful deduction and tenacious sleuthing, with Wong piecing together the sequence of events that connected the murder, the forged funds, and the supposedly secret planes. The resolution sheds light on the true aims behind the scheme, separating fact from rumor and exposing the people who tried to manipulate money, power, and fear to their advantage. The story remains grounded in a tense, noir-tinged atmosphere, where every clue, every conversation, and every shadow matters in revealing the truth behind a crime that began with a single, fatal dart.
