The detective raised himself to his knees and held his head high, listening. The roar of a motor being raced as it was switched off came to their ears.

"That's them," said the detective. "That was Gibson's signal. He was driving and he raced his engine to let us know when they got here."

They waited for years, it seemed to John, until two dark figures, scarcely discernible came down the tracks toward them and turned into the gully. He saw that Gibson and "Red Mike" were carrying something heavy between them and that "Red Mike" also carried a short-handled sledge hammer.

He strained his eyes trying to follow the figures into the darker shadows of the gully from which they emerged shortly.

"That's the derailer they're carrying—they're going to slap it on the rail," breathed the detective.

They could hear "Red Mike" grunting as he and Gibson struggled up the side of the roadbed. They saw "Red Mike" adjust the derailer to the rail and Gibson kneel to hold a spike as it was hammered into the tie by "Red Mike" wielding the sledge hammer. The blows of the hammer sounded sharply on the still night air. They heard "Red Mike" curse viciously as he missed hitting the spike and Gibson jerked his hand away a fraction of a second before the sledge would have smashed it against the rail.

Four spikes were driven to hold the derailer. Then Gibson and "Red Mike" scrambled back into the gully, their figures hidden in the darkness.

"All set down there," whispered the detective, thus conveying to the others the realization that the derailer was in place to swerve the guiding wheels of the big locomotive of the "Lark" and send it crashing into the ditch, pulling and overturning the coaches with it.

The horror of what might happen terrorized John for a moment. His body tingled and perspiration broke out on his forehead. He closed his eyes. He imagined he would hear the roar of the train as it crashed into the derailer and rolled over the embankment—the screams and cries of the dying and injured. A sickening feeling swept him. He was faint. He could hear Brennan breathing deeply, the breath whistling out through his teeth from his lungs.

"Gosh darn!" Benton gasped, as though he could hold himself no longer.