Charlie Chan [Warner Oland] is summoned to Egypt when an archaeologist disappears during a tense excavation of ancient art treasures, triggering a web of motives and secrets that Chan must untangle. He must sift through competing stories from the expedition team, confront the crazed son of the missing scientist, and uncover why priceless treasures keep turning up in private collections, all while facing a series of seemingly supernatural events that only deepen the mystery.
Chan’s first steps take him from a rickety biplane to a desert trek by pack mule, a journey punctuated by his dry witticisms and a sharp eye for danger. > Offspring of Satan. He presses himself through the heat and sand, determined to separate superstition from evidence and to keep his investigation firmly grounded in science and reason, never letting fear guide his conclusions.
At Professor Arnold’s mansion, George Irving portrays Professor Arnold, the missing scholar whose daughter Carol Arnold Pat Paterson fiercely defends her father against charges of dishonesty. Carol’s relationship with her boyfriend Tom Evans Thomas Beck adds another layer to the mounting tension, while Carol’s brother Barry Arnold [James Eagles] lingers on the edges of the family drama, his violin music coloring the atmosphere with melancholy. Nearby, the servant Nayda Rita Hayworth moves about the household with a quiet, unsettling presence, and the pale lines between loyalty and deceit begin to blur as the case unfolds. Dr. Anton Racine [Jameson Thomas], who has extended a large loan to keep the expedition afloat, and Professor Thurston [Frank Conroy], who confesses that some items that later surface in museums were sold to replenish funds, knit a financial knot that Chan will need to untie. The household is rounded out by the dutiful Inspector Fouad Soueida [Paul Porcasi], who maintains formality even as he proves himself capable.
In the hidden laboratory beneath the mansion, a full scientific setup catalogs every discovery, and Chan quickly notices the seal on a sarcophagus has been broken. When a quick X-ray exposes a 20th‑century bullet lodged in the mummy, the truth becomes clear: the corpse in the sarcophagus is Professor Arnold’s—bloodless and mummified to hide the crime from plain sight, a haunting reminder that the motivations here run far deeper than simple greed.
Carol begins to suffer unexplained sleepiness and anxiety, and Chan identifies the source: her personal cigarettes have been laced with a hallucinogenic drug. The case intensifies when Barry Evans dies during a performance, the high note from his violin shattering a glass vial containing poison gas, a method that reveals the killer’s specialized knowledge of modern science rather than anything supernatural.
As the investigation widens, Tom Evans joins Chan’s perilous nighttime exploration of a tomb that can only be reached underwater. They uncover a secret chamber filled with looted treasures and elaborate ghost disguises, a chilling tableau that the killer uses to mislead those who stumble upon it. The murderer shoots Tom point-blank in this hidden room, and Chan and Snowshoes manage to return the wounded man to the mansion, where Tom hovers between life and death. Chan declares that since the shooter struck him from the front, the killer’s identity will become clear once Tom recovers enough to speak.
The climax unfolds as Chan and a small cadre of Egyptian police lay a careful trap, capturing the killer and bringing him to justice. In the aftermath, Chan reflects on the case as he watches Carol and Tom embrace, recognizing that this simple moment of human connection is the reward he sought for his relentless pursuit of the truth.
