generator room,connecting banks of tubes, stringing an aerial on the terrace.
"Twelve hours! Twelve hours!" he muttered. "Just time to make it ifthe doctor's calculations are correct. June, hand me those pliers, butbe careful of the wires. I haven't time to insulate them. When westart the dynamo they'll be carrying twelve thousand volts."
"But won't Solinski and his men come back and kill us?" For the firsttime the full weight of despair descended upon her brave spirit.
"Probably. Does your father have a revolver?"
"I--I think so."
"Find out." Jack connected a loading coil with deft fingers. "Then godown to a sporting goods store and get some ammunition. If there areany shotguns in the place bring two back with plenty of buckshotshells. I don't think we're being watched yet, but if you're attacked,run for it."
Noting she looked hurt at his abruptness, he kissed her quickly.
"Sorry, darling. Every second counts. Run along, like a good girl."
She smiled for the first time in a long while and patted his hand.
* * * * *
When she returned, two shotguns and several boxes of shells held likewood in her bent arms, the generator was sparkling merrily. Thegasoline engine barked steadily and the vacuum tubes glowed green.
Manthis came in at that moment and injected all the remaining drug asJack gave crisp orders. Automatically the engineer had taken command.
"I'll get things going and handle the dials until Solinski sends hisrats down on us. June, you watch the street door. Run up at the firstsign of an attack. After that you'll take my place and hold it, nomatter what happens, until we succeed or are killed. The doctor and Iwill go downstairs when you come up, and hold them off or retreatslowly. Thank heaven we can command both the front and rear stairwaysfrom the halls. Now doctor, watch the circuit breaker. I'm going tothrow on full power."
As he advanced the rheostat the tubes glowed brighter, bathing theroom in unearthly light. Jack adjusted his headset, and smiled up atJune. She kissed him bravely before hurrying to her dangerous post.
Once more he sat listening to that whining, fluctuating wave. Theengineer's thoughts wavered between speculations on the future, fondmemories of June and impatience with the dragging hours. Would nothingever happen? Through the earphones now came a jangling, agonizedwhine, as if the two antagonistic waves were endowed with life andactually struggling in the ether.
From time to time his glance wandered to the child, who, havingobtained a head start through her preliminary treatment, now wasstirring fretfully.
Slowly the time plodded by. Jack smoked cigarette after cigarette inan effort to fight off the drowsiness which loaded his eyelids withlead.
It must have been three o'clock when a whimper from the divan apprisedthem that the child at last had awakened.
"Where's mama?" She blinked into the glare. "I've lost my mama."
"There, there, honey," soothed the doctor, stopping his pacing up anddown the room and picking her up. "Your mama had to go away forawhile. She'll be back any minute. Let's go find a drink of water. AndI've something for you to play with too." Gently he carried her intoJune's bedroom.
Soon he reappeared and patted Jack on the shoulder.
"Our first victory," he said in a broken voice. "She's in perfectcondition and sleeping naturally now. I gave her one of June's olddolls to play with." He sighed and collapsed into the nearest chair."I'm almost dead with the strain of it. Do you think there's achance?"
"Three more hours should turn the trick. I don't understand whySolinski--"
The crash of a shotgun, coming faint but clear from the street below,brought him up short. The shot was answered by a volley of rifle fire.
* * * * *
Jack almost lost the wave in his excitement, but regained it with adesperate twist of the wrist. No time for nerves now. He must be calm!
"Go down and hold them until June can get back to relieve me," heordered. "Hurry. They may rush her any moment."
The doctor seemed ten years younger as he thrust a revolver into hispocket, snatched a shotgun from behind the door and ran out.
The commotion had awakened the child, who started whimpering, addingfurther to Jack's distractions. Yet he managed, in spite of ghastlymental pictures of June being torn to pieces by her attackers, to keephis hands steady.
A few minutes later she slipped into the room and laid her cold cheekagainst his before taking her place at the instruments.
"It's all right," she added. "I don't think they'll attack in thedark. There are five of them. I'm sure I wounded or killed one. Theyweren't expecting a guard. I left the gun with father. He's behind thecashier's desk." Then, all her courage evaporating, she turned anappealing, little girl face toward her lover. "Don't let yourself bekilled, Jack. I'd die too."
"June, you're wonderful," he whispered. "I didn't know there was agirl alive as brave as you. Good-by. No matter what happens, keep thewave in tune." He kissed her tenderly, trying not to think he had doneso for the last time, and hurried out.
The stairs were black as the inside of a tomb. Once he stumbled overthe body of a charwoman and came near falling headlong.
"Nothing's happened since that first volley," whispered Manthis whenJack slipped into the cage. "They're holding off for dawn. Look!" hisvoice wavered. "Was that a face at the window?" He fired wildly. Glasstinkled.
"Easy," warned Baron. "Don't waste ammunition. Besides, if you getthis place full of smoke they'll jump us."
* * * * *
Dawn was painting the windows gray when the assault began. Their firstwarning came when a small object was tossed into the lobby. Itexploded in a cloud of white vapor.
"Tear gas," yelled Jack. "Back to the stairs." They ran for cover,weeping and choking.
Then began a slow retreat up the stairways, Jack guarding the frontand Manthis the back passages. At first it was a simple matter fortheir enemies to toss tear bombs through the fire doors, then,protected by respirators, capture another floor. But as the lightincreased this became more and more hazardous. Twice a spray ofbuckshot laid a Solinski man low.
"He hasn't many men available," called Jack as the attack slackened."But watch out. His time's about up. Hey, look at that woman!" Awhite-uniformed maid, whom he remembered having seen lying in the samespot every time he climbed the stairs, had stirred weakly, as thoughabout to wake.
It was their glance at the sleeping form which undid them. When theylooked up both fire doors were open and helmeted figures were emergingfrom them.
The shotguns roared. Two of their attackers collapsed, but the otherscame on. Before there was time for another shot they were at closequarters. Standing back to back, Manthis and Jack clubbed their gunsand held their ground.
The fact that Solinski and his men wore respirators handicapped themimmensely, so that the two defenders kept a cleared circle about them.
One of the attackers, more daring than the rest, leaped forward toengage the engineer. He collapsed with a crushed skull.
Then, when victory seemed in their grasp, luck turned. At Jack's nextblow the stock of his weapon parted from the barrel, leaving himalmost defenseless. At the same time Manthis slipped and collapsedfrom a knife thrust.
* * * * *
Jack was left alone to face three enemies and would have been killedwithin the minute had not Solinski, recalling the little time he hadleft to stop the interfering wave, deserted his comrades and sprintedfor the laboratory.
The seeming defection of their chief threw the other two attackersinto momentary confusion. Before they could recover, Jack knocked oneout with the gun barrel, then came a flying tackle at the other.
But he had caught a tartar. His remaining enemy was a gigantic Negro.Recovering from his surprise the latter lifted high a glittering knifeto finish his disarmed foe. Jack snatched at the uplifted arm--missed!
A revolver cracked.
The hooded Negro staggered, then crashed forward.
"Remembered my pistol just in time," gasped the doctor from the floor."Don't bother about me. I'm all right. Stop Solinski, for God's sake."
Although his lungs seemed bursting Baron turned and flew up thestairs. Being familiar with every turn, he gained on the Russian andcaught sight of the dreadful black coat-tails as his enemy burstthrough to the twentieth floor. The locked door of the apartmentbaffled him only a moment. Stepping back, Solinski hurled his giantframe against the panels. They splintered and crashed inward. But thedelay allowed Jack to catch up.
He leaped on the Russian's back. Locked together they