Dane remained where he was until it had almost reached the deck of the next level and then he followed, one step at a time.  He was sure that the Hoobat’s peculiar construction of body prevented it from looking up—­unless it turned upon its back—­but he did not want to do anything which would alarm it or deter Queex from what he was sure was a methodical chase.

Queex stopped again at the foot of the second descent and sat in its toad stance, apparently brooding, a round blue blot.  Dane clung to the ladder and prayed that no one would happen along to frighten it.  Then, just as he was beginning to wonder if it had lost contact with its prey, once more it arose and with the same speed it had displayed in the Captain’s cabin it shot along the corridor to the hydro.

To Dane’s knowledge the door of the garden was not only shut but sealed.  And how either the stranger or Queex could get through it he did not see.

“What the—?” Ali clattered down the ladder to halt abruptly as Dane waved at him.

“Queex,” the Cargo-apprentice kept his voice to a half whisper, “it got loose and chased something out of the Old Man’s cabin down here.”

“Queex—!” Ali began and then shut his mouth, moving noiselessly up to join Dane.

The short corridor ended at the hydro entrance.  And Dane had been right, there they found the Hoobat, crouched at the closed panel, its claws clicking against the metal as it picked away useless at the portal which would not admit it.

“Whatever it’s after must be in there,” Dane said softly.

And the hydro, stripped of its luxuriance of plant life, occupied now by the tanks of green scum, would not afford too many hiding places.  They had only to let Queex in and keep watch.

As they came up the Hoobat flattened to the floor and shrilled its war cry, spitting at their boots and then flashing claws against the stout metal enforced hide.  However, though it was prepared to fight them, it showed no signs of wishing to retreat, and for that Dane was thankful.  He quickly pressed the release and tugged open the panel.

At the first crack of its opening Queex turned with one of those bursts of astounding speed and clawed for admittance, its protest against the men forgotten.  And it squeezed through a space Dane would have thought too narrow to accommodate its bloated body.  Both men slipped around the door behind it and closed the panel tight.

The air was not as fresh as it had been when the plants were there.  And the vats which had taken the places of the banked greenery were certainly nothing to look at.  Queex humped itself into a clod of blue, immovable, halfway down the aisle.

Dane tried to subdue his breathing, to listen.  The Hoobat’s actions certainly argued that the alien thing had taken refuge here, though how it had gotten through—?  But if it were in the hydro it was well hidden.

He had just begun to wonder how long they must wait when Queex again went into action.  Its clawed front legs upraised, it brought the pinchers deliberately together and sawed one across the other, producing a rasping sound which was almost a vibration in the air.  Back and forth, back and forth, moved the claws.  Watching them produced almost a hypnotic effect, and the reason for such a maneuver was totally beyond the human watchers.