“What!” The doctor leaped to their sides.  He took it in at a glance; then whirled to the door.  “We ought to warn Estra!”

“He knows it already!” reminded Billie swiftly.  A great shout came from below; the attackers had forced their way through the crowd of Estra’s friends.

“Well!” Van Emmon stood squarely in the middle of the room.  “So far as I’m concerned, Estra and his sister can face that crowd alone!  I don’t approve of the scheme!”

The doctor eyed him thoughtfully.  “I’m not so sure, Van.  This is a tremendous thing; we ought to—­”

“Van is—­right!” exploded Billie.  Her voice rose to a shriek as a crash shook the house.

Next instant Myrin, for once in a hurry, broke into the room.  She glanced about, missed Estra, looked slightly puzzled, and then frowned angrily as the Venusian himself stepped in:  “You fooled me!” she shot at him.  But he smiled apologetically.  He was carrying a large package of leaflets, closely printed in Venusian; there seemed to be several thousand in the lot.  He said, by way of explanation: 

“I had to get ready.  Savarona’s people will be here any moment; they have destroyed the elevator, and—­”

A wave of clamor burst from below.  “They’ve broken the barrier,” remarked Estra calmly; he turned to the door, then whirled at a crash which sounded from above.  “Through the roof,” he added.  He did not even glance at the balcony, where the two cars barred the way against any attack from that direction.

Next second he again quit the room.  Myrin hesitated a moment, irresolute, and then followed him thoughtfully.  They never saw her again.  As for Estra, he came back in a moment carrying a small, white bundle, which stirred in his arms.  He unhesitatingly handed the child to Billie.  His mouth moved soundlessly as a muffled shriek arose from the other end of the corridor; there was a thud, a metallic crash, and a great roar of voices.  The mob had broken in, and up, through the back of the house.  The first of the attackers thrust his head and shoulders into sight not ten feet away.

Estra touched something with his foot, and a door shot across the corridor.  There was an instant’s silence; then, the thunder of the mob, hurling itself against the door.  The people were fairly snarling now.  Estra closed the inner door.

“Estra!” shrilly, from Billie.  She laid the baby down, and strode to the Venusian.  “Let’s get out of here!  The car’s on the balcony; nobody’s in the way to interfere!  Why not—­”

A grinding, ripping jar from above, and Estra shook his head.  The smile was gone, and his mouth was set and grim.  “They’d catch us before we went a mile,” he said, glancing at the infant, who had begun to cry, in a stifled, gasping way that tore at the nerves.

“Estra!” Billie pleaded; but he turned away.  The doctor strode up to him and gripped his shoulder.

“What’s the good, Estra?  What can you accomplish even if you—­”