Thousands of busy persons bent over their desks in the tallest building in the world—conducting the commerce of the nation—when suddenly the steel girders began to creak and twist, and the gigantic edifice swayed giddily in the rising wind. Never before had criminal brains devised a more cunning or a more horrible weapon to garner their ill-gotten treasures. And never before was the Spider so strenuously put to test—for the Master, the man behind the devastation and death, eluded every suspicion, foresaw every contingency, left no tell-tale clues behind him as he ravaged, slayed and pillaged… Richard Wentworth, working for once hand in hand with the organized forces of law and order, fights the grimmest battle of his long career. Can the Spider avenge the countless dead who have already fallen? Can he bring the Murder Master to the justice he so richly deserves?

By what strange twist of Fate did the fearful menace which was to shadow every man and woman in New York City first rear its venomous head in the distant Caribbean? When terror suddenly boarded a little tramp steamer and left crimson havoc littering its narrow decks a spluttering wireless flashed the doom of every living thing aboard. Within a week, the same ghastly fate struck a gigantic new ocean liner, its luxurious cabins occupied by the elite and powerful of a dozen different nations! Death—swift and terrible—rode the ocean lanes. And the Spider—taken for once off guard—was supposedly dying in a hospital room on the very day when that terror from the seas first showed itself in all its terror above the city skyline. How can the Spider, fighting death himself, help the nation he loves in her hour of greatest need?

Thundering far beneath Manhattan’s thronging streets came the Death Express—a crack New York Central train bearing a gruesome cargo of lifeless men, women and children—their bodies stripped of valuables, naked and mutilated! A grim warning of the terror-reign that threatened America—at the hands of Twentieth Century land-pirates, whose weapon was neither gun nor sword, but the stunning, body-shivering force which lies in electricity! Can the Spider, using mortal weapons, fight the numbing power of the thunderbolt—and survive?

When the Underworld united in one compact army of crime, the Spider—his prestige gone—faced the most vicious collection of criminals and degenerate killers ever assembled under one dark banner of bloody social war! How can Richard Wentworth, robbed of Kirkpatrick and Nita, renew the Spider-fear which alone can bring him victory from a menace that is making casualty columns of our daily papers and filling our institutions with driveling victims of the new madness?

The Flaming Shadows fell upon the city, shrouding whole neighborhoods in a fiery gloom—wherein walked screaming death and merciless destruction… Go with the Spider as he battles, single-handedly, the Flaming Shadows—to save the very people who pray for his destruction!