ade my get-away I couldn't kill them all, of
course, and I thought maybe they might connect things up with my
jail-break and tell the other cities to take steps about you two. But I
guess they're pretty well disorganized back there yet, since they can't
know who hit them, or what with, or why. I must have got about everybody
that wasn't sealed up somewhere, and it doesn't stand to reason that
those who are left can check up very closely for a while yet. But
they're nobody's fools--they'll certainly get conscious when I snatch
you, maybe before ... there, I see your city, I think."

"What are you going to do?"

"Same as I did back there, if I can. Poison their primary air and all
the water I can reach...."

"Oh, Conway!" Her voice rose to a scream. "They must know--they're all
getting out of the water and are rushing inside the buildings as fast as
they possibly can!"

"I see they are," grimly. "I'm right over you now, 'way up. Been
locating their primary intake. They've got a dozen ships around it, and
have guards posted all along the corridors leading to it; and _those
guards are wearing masks!_ They're clever birds, all right, those
amphibians--they know what they got back there and how they got it. That
changes things, girl! If we use gas here we won't stand a chance in the
world of getting old Bradley. Stand by to jump when I open that door!"

"Hurry, dear! They are coming out here after me!"

"Sure they are." Costigan had already seen the two Nevians swimming out
toward Clio's cage, and had hurled his vessel downward in a screaming
power dive. "You're too valuable a specimen for them to let you be
gassed, but if they can get there before I do they're traveling fast!"

He miscalculated slightly, so that instead of coming to a halt at the
surface of the liquid medium the speedster struck with a crash that
hurled solid masses of water for hundreds of yards. But no ordinary
crash could harm that vessel's structure, her gravity controls were not
overloaded, and she shot back to the surface; gallant ship and reckless
pilot alike unharmed. Costigan trained his key-tube upon the doorway of
Clio's cell, then tossed it aside.

"Different combinations over here!" he barked. "Got to cut you out--lie
down in that far corner!"

His hands flashed over the panel, and as Clio fell prone without
hesitation or question a heavy beam literally blasted away a large
portion of the roof of the structure. The speedster shot into