e at night.

For several days in the latter part of August there had been nightly
frosts. Then there had been a short spell of warm weather and this night
the boys could see that cool weather was rapidly approaching. As the
monoplane winged its way into the gathering gloom and the crisp evening
passed into dusk, the body of the _Gitchie Manitou_ grew wet with cold
dew. After dark, this began to turn into frost. Paul was able to wrap a
light blanket about himself, but Norman, with no relief present, stuck to
his post, protected only by his gloves and sweater.

As it was impossible to make out the course of the river from any
distance, he had to defy the air currents in the rather hazardous light
between the high river banks. It was far from the even flight made during
the day in the sunlight, and again Norman could see his companion
gripping the edge of the cockpit. There was little conversation, and in
order to divert his companion, Norman manufactured a job for Paul by
assigning to him the duty of watching the engine revolution gauge and the
chronometer.

As Paul flashed the bulbs, throwing their little shaded lights on these
instruments, and sang out the reading every few moments, Norman could not
resist a smile. He read both instruments each time as quickly as his
assistant.

About eleven thirty, the sun having now wholly disappeared, Norman's
long-waiting ear caught the unmistakable roar of the head of the Grand
Rapids. From this place, he had a compass bearing to Fort McMurray, and
he could have predicted their arrival at the camp almost within minutes.

"You can take it easy now," he suggested to Paul. "We're practically
home."

When the roar of the Rapids finally ceased, the river fog cleared
somewhat and, with the help of the stars, the outline of the river became
plainer below.

"How much longer?" asked Paul in a tired tone.

"We've been coming pretty slow," was Norman's cheery response. "We'll hit
her up a bit. It's forty miles to the camp, but we'll save a little by
cutting out the big bend. See if I ain't there in three-quarters of an
hour."

"I'd think they'd have a light for us."

"If they're all asleep," answered Norman.

But they were not asleep. Some apprehension on the part of even Roy had
kept him and the colonel wide awake. When it grew dark and the monoplane
had not returned, he made a fire of cordwood and during the long evening
renewed it constantly. At half past one the _Gitchie Man