Even when Riki—muffled like the rest—waved to him from the mouth of the tunnel, his spirits did not lift. The thing he wanted was to look forward to years and years of being with Riki. He wanted, in fact, to look forward to forever. And there might not be a tomorrow.
"I had the control board rolled out here," she called breathlessly through her mask. "It's cold, but you can watch!"
It wouldn't be much to watch. If everything went all right, some dial-needles would kick over violently, and their readings would go up and up. But they wouldn't be readings of temperature. Presently the big grid would report increased power from the sky. But tonight the temperature would drop a little farther. Tomorrow night it would drop farther still. When it reached one hundred and nine point three degrees below zero at ground-level—why it would keep on falling indefinitely. Then it wouldn't matter how much power could be drawn from the sky. The colony would die.
One of the figures that looked like a bear now went out of the mine-mouth, trudging toward the grid. It carried a muffled, well-wrapped object in its arms. It stooped and crept between the spokes of the grid. It put the object on the stone. Massy traced cables with his eyes. From the grid to the control board. From the board back to the reserve-power storage cells, deep in the mountain.
"The grid's tuned to the bomb," said Riki breathlessly, close beside him. "I checked that myself!"
The bearlike figure out in the valley jerked at the bomb. There was a small rising cloud of grayish vapor. It continued. The figure climbed hastily out of the grid. When the man was clear, Massy threw a switch.
There was a very tiny whining sound, and the wrapped, ridiculously smoking object leaped upward. It seemed to fall toward the sky. There was no more of drama than that. An object the size of a basketball fell upward, swiftly, until it disappeared. That was all.
Massy sat quite still, watching the control-board dials. Presently he corrected this, and shifted that. He did not want the bomb to have too high an upward velocity. At a hundred thousand feet it would find very little air to stop the rise of the vapor it was to release.
The field-focus dial reached its indication of one hundred thousand feet. Massy reversed the lift-switch. He counted and then switched the power off. The small, thin whine ended.