1943's "The Mad Ghoul" remains a sadly neglected entry during a year in which horror was in short supply at Universal, positioned at the bottom of a double bill with Lon Chaney's "Son of Dracula." Lionel Atwill had scored as mad scientists in both "Man Made Monster" and "The Mad Doctor of Market Street," but since then only John Carradine carried on the tradition with "Captive Wild Woman," spawning two sequels in its wake, "Jungle Woman" and "The Jungle Captive." On just this one occasion George Zucco received the call to star as Dr. Alfred Morris, whose experiments result in tragedy as delusions of unrequited love are not reciprocated. Dr. Morris is teaching classes at University City, selecting skilled surgeon Ted Allison (David Bruce) to become his prize pupil, after discovering the secret behind the Mayan technique of human sacrifice, cutting out the hearts of living donors not to appease their gods but to restore life to victims of a deadly gas that leaves the subject in a fearful state of 'death in life,' feted to die without treatment. The doctor has been able to recreate the gas and indoctrinated a monkey as a guinea pig, requiring Ted to perform a cardiectomy on another monkey for the heart substance, when mixed with certain herbs serving as a cure for the zombie-like condition. The little creature seems totally unaffected by its ordeal and all goes well, Dr. Morris also rejoicing in Ted's relationship with concert singer Isabel Lewis (Evelyn Ankers), as he secretly covets the young lovely for himself. Once Morris becomes aware of Ted's intention to marry Isobel he sets a trap for his naïve assistant, who becomes a human victim of the Mayan gas, a slave to the will of his master. Unfortunately, the happy go lucky monkey soon falls back into his living death state, the cure merely a temporary one, too late for Dr. Morris to make amends so he and Ted follow Isobel's singing tour from town to town, every relapse requiring a desecration of the recently interred for heart substance. More grim than the usual Ben Pivar production, the extensive gruesomeness is kept off screen, but as one caretaker supplies a fresh heart, so too does a (too) clever reporter (Robert Armstrong) pretending to be a corpse lying in a coffin, his accurate hunch proving to be a fatal one. George Zucco only received star billing at Poverty Row's PRC in titles like "The Mad Monster," "Dead Men Walk," "The Black Raven," "Fog Island," and "The Flying Serpent," so to essay a more nuanced villain at Universal was a nice change, though he does indulge his bulging eyes toward the end of the film when confessing his indiscretion to Ted (we reveled in Atwill's madness but never felt sympathy for him). His previous mad scientists at Paramount ("The Monster and the Girl") or Fox ("Dr. Renault's Secret") were smaller roles rather than the lead, an established supporting fixture at Universal in "The Mummy's Hand," "Dark Streets of Cairo," "The Mummy's Tomb," "The Mummy's Ghost," and "House of Frankenstein," so at least here he's allowed to effortlessly carry a star vehicle for a major studio. Top billed David Bruce only had one other genre credit opposite Lon Chaney in "Calling Dr. Death,," wearing a close facsimile of Boris Karloff's makeup as Ardath Bey in "The Mummy," later worn by Chaney himself in "Man Made Monster," a Jack Pierce application meant to show the character's gradual disintegration into a dessicated corpse.
