always safe to judge by the looks of a flea how
far he can jump!"

He stepped out through the opening into the water, and, burdened as he
was, made shift to swim to the nearest ramp. Up it he ran, toward a main
corridor. But ahead of him there was wafted a breath of dread Vee-Two,
and where that breath went, went also unconsciousness--an
unconsciousness which would deepen gradually into permanent oblivion
save for the prompt intervention of one who possessed, not only the
necessary antidote, but the equally important knowledge of exactly how
to use it. Upon the floor of that corridor were strewn Nevians, who had
dropped in their tracks. Past or over their bodies Costigan strode,
pausing only to direct a jet of lethal vapor into whatever branching
corridor or open doorway caught his eye. He was going to the intake of
the city's ventilation plant, and no unmasked creature dependent for
life upon oxygen could bar his path. He reached the intake, tore the
canister from his back, and released its full, vast volume of horrid
contents into the primary air stream of the entire city.

And all throughout that doomed city Nevians dropped; quietly and without
a struggle, unknowing. Busy executives dropped upon their cushioned,
flat-topped desks; hurrying travelers and messengers dropped upon the
floors of the corridors or relaxed in the noxious waters of the ways;
lookouts and observers dropped before their flashing screens; central
operators of communications dropped under the winking lights of their
panels. Observers and centrals in the outlying sections of the city
wondered briefly at the unwonted universal motionlessness and
stagnation; then the racing taint in water and in air reached them, too,
and they ceased wondering--forever.

Then through those quiet halls Costigan stalked to a certain storage
room, where with all due precaution he donned his own suit of
Triplanetary armor. Making an ungainly bundle of the other Solarian
equipment stored there, he dragged it along behind him as he clanked
back toward his prison, until he neared the dock at which was moored the
Nevian space-speedster which he was determined to take. Here, he knew,
was the first of many critical points. The crew of the vessel was
aboard, and, with its independent air-supply, unharmed. They had
weapons, were undoubtedly alarmed, and were very probably highly
suspicious. They, too, had ultra-beams and might see him, but his very
closeness to them would t