D-99 by H. B. Fyfe
S science fiction thriller of alien invasion.
ROCKETS SLAMMED PAST
—just missing the tall, gaunt man who dodged down the stairs of the Earth Embassy. A figure loomed in a doorway and he snapped off a quick blaster shot at it—missed.
He'd killed one man, wounded others—and was carrying papers stolen from the secret Embassy files. They had to stop him—but they couldn't!
—And, worlds away, the men of Department 99 watched on their galaxy-spanning view-screen ... knowing they were responsible for this disaster—and powerless to do anything about it!