The Treasure-Train

A railroad Vice President and and his chauffeur have sudden and mysterious seizures on the way to work; a family in New York city undergoes an epidemic of beri-beri; the American consul in the Virgin Islands collapses and dies for no apparent reason; a Wall Street speculator is apparently stabbed to death--with a rubber dagger. Who other than Craig Kennedy, armed with his knowledge of chemistry, technology and Freudian psychology could solve these mysteries?