With the location just over the border of Communist China and a thinking man's hero (doctor-and-scientist), this routine, expediently told tale of Marx and medicine would fit in nicely just before the eleven o'clock news. Returning to the ""enchanted land"" of Muong Toa, Dr. John Merchant arrives to find his beloved guardian and teacher, Dr. Oscar Thornton -- the Schweitzer of Muong Toa -- dying, and Thornton's son Chan on the brink of a great discovery in microbiology -- a species of Chlorella that reproduces faster than any other living thing. Realizing that test-tube production of food is near at hand, Dr. Merchant with the lovely Indra (another Thornton prodigy), and Merchant's assistant Dud Porter join forces with Chan in pressing forward with their revolutionary experiment. The Chinese Communists are not unaware of the doings at the Thornton hospital and lab, and after old Thornton's death Merchant begins to suspect that Chan is leaning toward a closer relationship with the Chinese. Some detective work by Merchant reveals Chan's dissembling and there is a wildly implausible Fu Manchu climax. Chan is finalized explosively and our men take the secret formula to Washington. Predictable and lacks the dash of his earlier historicals.