Thad was still studying the picture, thoughtfully and sadly, when the dog, which had been silent, suddenly growled again, and retreated from the door, toward the corner of the room.
The invisible monster had returned. Thad heard its claws scratching across the door again. And he heard another dreadful sound—not the long, shrill scream that had so grated on his nerves before, but a short, sharp coughing or barking, a series of shrill, indescribable notes that could have been made by no beast he knew.
The decision to open the door cost a huge effort of Thad's will.
For hours he had waited, thinking desperately. And the thing outside the door had waited as patiently, scratching upon it from time to time, uttering those dreadful, shrill coughing cries.
Sooner or later, he would have to face the monster. Even if he could escape from the room and avoid it for a time, he would have to meet it in the end. And it might creep upon him while he slept.
To be sure, the issue of the combat was extremely doubtful. The monster, apparently, had succeeded in killing every man upon the flier, even though some of them had been armed. It must be large and very ferocious.
But Thad was not without hope. He still wore his Osprey-suit. The heavy fabric, made of metal wires impregnated with a tough, elastic composition, should afford considerable protection against the thing.
The welding arc, intended to fuse refractive meteoric iron, would be no mean weapon, at close quarters. And the quarters would be close.
If only he could find some way to make the thing visible!