The descent, on such a makeshift power car as the speeder, was fraught with greater perils than the climb up the mountain. No power would be necessary, for the car would go fast enough without any added impetus. In order to keep it from going too fast, and jumping the track, the brakes would have to be judiciously used.

"We're off!" cried McGlory, as the speeder began coasting down the grade.

Matt tried out the brakes. They were capable of slackening the pace, but as for stopping the car, no appliance could have done that.

With rear wheels locked, the speeder hurled itself down the mountain, acquiring greater and greater speed as it went. In and out of cuts the car dashed, here and there rumbling over a trestle which gave the passengers fearful glimpses of space below them.

McGlory and Bunce hung to their bench with both hands. There was no talking, now, for all three passengers were holding their breath.

Finally the descent became less steep. As the grade flattened out slowly into something approaching a level, Matt's work with the brakes began to achieve results. By degrees the mad flight of the car commenced to slacken.

"Sharp curve ahead!" sang out McGlory, heaving a deep breath of relief as the car continued to slow down.

Matt saw the sharp turn in the track where it rounded a shoulder of rock. Naturally he could not see around the turn, and he was speculating as to whether their reduced speed would be sufficient to throw the speeder off the rails at the bend, or whether the car would make it safely.

Before his calculations had been brought to an end, the problem was working itself out.

The speeder struck the curve, whirled around it with a shrieking of flanges against the rails, and then there went up a wild yell from McGlory and Bunce.