it will be
slaughter. We've still got a chance, Craig."

"You're damned right we have!" the big man answered.

"Except," the captain continued thoughtfully, "for ammunition, food, and
water, we're all right."

"If we're not out of here by the time our ammunition runs out, we'll
never escape," Craig answered. "However, we'll be out of here in an
hour."

"I hope you know what you're talking about," was Higgins' only comment.

The Ogrum were making no attempt to attack. Craig circled the roof of
the temple, seeing that sub-machine guns covered all approaches. A wind,
moving from the direction of the swamp, brought with it the sound of the
dinosaurs. The scene was like a setting from some fantastic movie--a
full moon burning like a huge fire on the horizon, incredible beasts
screaming in the night, a group of embattled humans on the roof of a
temple as old as time.

"We've got them!" Craig thought. "They can't get to us and they don't
dare attack. If they wait an hour--"

* * * * *

In some hidden spot outside the temple something went _plunk_. The sound
was not sharp enough to be called an explosion. It was a plunk, like a
rock falling in a rain barrel.

A small round object arched slowly through the air and hit on the roof
of the temple. It also went _plunk_. No explosion. Just a _plunk_. A
cloud of white smoke puffed out.

"What the devil is that?" Craig thought uncertainly. "Are they throwing
grenades at us? Was the first grenade a dud?"

He started toward the grenade. A whiff of the smoke stung his nostrils,
sent a warning bell clattering wildly in his brain.

"Gas!" he yelled. "They're throwing gas grenades at us. Stay away from
that smoke."

The Ogrum had attacked the Idaho with their sleeping gas! The guards in
the temple had carried sacks of what Craig had thought were ordinary
grenades. They had been gas grenades!

_Plunk_ went the projector outside the temple. _Plunk_ went the grenade
that struck on the roof.

_Plunk, plunk, plunk_--A shower of grenades came over. Gas swirled over
the roof of the temple.

"Knock out those projectors!" Craig shouted. He leaped to the wall of
the temple, began firing. All around him other guns were letting go. Up
to now it had been necessary to conserve ammunition as much as possible.
If the projectors were not knocked out, no amount of ammunition would do
the humans any good.

The rattle of sub-machine guns was a continuous tu