ys he barely avoided the clutching white arms that
were extended, and little by little he decoyed the thing onward....

Then came the end. As Holmes was almost in front of the wrecked
machine, Sue saw him glance quickly aside--and, as if waiting for that
moment when he would be off guard, the monster whipped forward in a
great, reaching surge.

Sue's ragged nerves cracked: she shrieked. They had him! She started
forward, then halted abruptly. With a tremendous leap, Phil Holmes had
wrenched free and flung himself backwards. She heard his yell:

"Now!"

* * * * *

There was a sputter from the bottom of the outstretched borer; then,
like the crack of a whip, came a bellow of awful sound.

A thick cloud of dust reared up, and the ear-numbing thunder rolled
through the cavern in great pulsing echoes. And then Sue Guinness
understood what the young man had been about.

The disintegrators of James Quade's borer had sent a broad beam of
annihilation into the monster. His own machine had destroyed his
destroyer--and given his intended victims their only chance to escape
from the dread fate he had schemed for them.

Sue could see no trace of the creature in its pyre of slow-swirling
dust. Caught squarely, its annihilation had been utter. And then,
through the thunder that still echoed in her ear-drums, she heard a
joyful voice.

"We got 'em!"

Through the dusty haze Phil appeared at her side. He flung his arms up
exultantly, swept her off the ground, hugged her close.

"We got 'em!" he cried again. "We're free--free to go up!"

Professor David Guinness crawled from the borer. His face, for the
first time since the descent, wore a broad smile. Phil ran over to
him, slapped him on the back; and the older man said:

"You did it beautifully, Phil." He turned to Sue. "He had to decoy
them right in front of the disintegrators. It was--well, it was
magnificent!"

"All credit to Sue: she was my inspiration!" Phil said, laughing. "But
now," he added, "let's see if we can fix those dead rocket-tubes. I
have a patient up above--and, anyway, I'm not over-fond of this
place!"

* * * * *

The three had won through. They had blasted four miles down from the
surface of the earth. The brain of an elderly scientist, the
quick-witted courage of a young engineer, had achieved the seemingly
impossible--and against obstacles that could not have been predicted.
Death h