the drinks, served by fredericks, were based on a rather rough grade of bourbon, but barney welcomed them. there was an almost sick fascination in what was a certainty now: he was going to get the tube. that tremendous device was his for the taking. he was well inside mcallen's guard; only carelessness could arouse the old man's suspicions again, and barney was not going to be careless. no need to hurry anything. he would play the reserved role he had selected for himself, leave developments up to the fact that mcallen had carried the burden of his secret for twelve years, with no more satisfactory confidant than fredericks to trust with it. having told barney so much, mcallen wanted to tell more. he would have needed very little encouragement to go on talking about it now.

barney offered no encouragement. instead, he gave mcallen a cautiously worded reminder that it was not inconceivable they had an audience here, at which mcallen reluctantly subsided. there was, however, one fairly important question barney still wanted answered today. the nature of the answer would tell him the manner in which mcallen should now be handled.

he waited until he was on his feet and ready to leave before presenting it. mcallen's plump cheeks were flushed from the two highballs he had put away; in somewhat awkward phrases he had been expressing his gratitude for barney's generous help, and his relief that because of it the work on the tube now could be brought to an end.

"just one thing about that still bothers me a little, doctor," barney said candidly.

mcallen looked concerned. "what's that, mr. chard?"

"well ... you're in good health, i'd say." barney smiled. "but suppose something did happen to you before you succeeded in shutting the mcallen tube down." he inclined his head toward the locked door.

"that thing would still be around waiting for somebody to open it and step through...."

mcallen's expression of concern vanished. he dug a forefinger cheerfully into barney's ribs. "young man, you needn't worry. i've been aware of the possibility, of course, and believe me i'm keeping very careful notes and instructions. safe deposit boxes ... we'll talk about that tomorrow, eh? somewhere else? had a man in mind, as a matter of fact, but we can make better arrangements now. you see, it's really so ridiculously easy at this stage."

barney cleared his throat. "some other physicist—?"

"any capable physicist," mcallen said decidedly. "just a matter, you see of how reliable he is." he winked at barney. "talk about that tomorrow too—or one of these days."

barney stood looking down, with a kind of detached surprise, at a man who had just pronounced sentence of death casually on himself, and on an old friend. for the first time in barney's career, the question of deliberate murder not only entered an operation, but had become in an instant an unavoidable part of it. frank elby, ambitious and money-hungry, could take over where mcallen left off. elby was highly capable, and elby could be controlled. mcallen could not. he could only be tricked; and, if necessary, killed.

it was necessary, of course. if mcallen lived until he knew how to shut the tube down safely, he simply would shut it down, destroy the device and his notes on it. a man who had gone to such extreme lengths to safeguard the secret was not going to be talked out of his conviction that the mcallen tube was a menace to the world. fredericks, the morose eavesdropper, had to be silenced with his employer to assure barney of his undisputed possession of the tube.

could he still let the thing go, let mcallen live? he couldn't, barney decided. he'd dealt himself a hand in a new game, and a big one—a fantastic, staggering game when one considered the possibilities in the tube. it meant new interest, it meant life for him. it wasn't in his nature to pull out. the part about mcallen was cold necessity. a very ugly necessity, but mcallen—pleasantly burbling something as they walked down the short hall to the front door—already seemed a little unreal, a roly-poly, muttering, fading small ghost.

in the doorway barney exchanged a few words—he couldn't have repeated them an instant later—with the ghost, became briefly aware of a remarkably firm hand clasp, and started down the cement walk to the street. evening had come to california at last; a few houses across the street made dim silhouettes against the hills, some of the windows lit. he felt, barney realized, curiously tired and depressed. a few steps behind him, he heard mcallen quietly closing the door to his home.

the walk, the garden, the street, the houses and hills beyond, vanished in a soundlessly violent explosion of white light around barney chard.