A team of professional robbers break into a minor Spectrum Security Vault near the coast of New York, where "useless" documentation is kept, which proves quite valuable to the lawbreakers. Along with another gang member, they simulate a fake play-act for a forest lookout warden, just on the outskirts of the American capital as hopeless, potentially dangerous drunks. They set-up their car with fake lookalike puppets to deceive the warden into thinking that the 3 drunken men that he just warned has helplessly crashed off the high mountainous road, and exploded in a fireball.
The gang then takes care of the warden and, deliberately posing as Mysteronised humans, they announce the force's latest plan to destroy the Second National Bank of New York, however the real Mysterons have yet to announce this at all, except for stating that they will destroy "The Heart of New York", but Colonel White understands that the bank is more than vital to fulfill the threat, as it stocks the entire gold reserve for the whole Eastern Seaboard of the country.
The robbers nevertheless intend to achieve their goal, again by posing as senior agents of the Federal Bureau of Investigation, and succeed in gaining entry through the Spectrum roadblock. With the entire American city evacuated, the bank is a sitting-duck, but Captain Black is awaiting their arrival, and only has fatal intentions in mind