“No.  Just got here.  Haven’t investigated yet.  Will listen in every quarter hour, beginning with the hour.”

“All right.  I’ll be here.  Good-bye.”

The minute Charley finished talking with Willie, the three investigators set about their work.

“We’ll walk along the edge of the burned area,” said the forester, “and try to find the point of origin.”

He went ahead, the two boys following.  They were facing toward the brook.  The line was irregular, like a huge saw-blade, with little jutting, black teeth here and there, where the flames had crept out in advance of the main line.  The wind that had come up when the boys were fighting the fire had driven the flames back upon the area they had already consumed and the blaze had died out of itself.  It could not eat its way to windward out here in the open, as it could have done in the dense timber where the wind was broken.  From their starting-point they walked to the brook, finding nothing to enlighten them.  They then retraced their steps, walking along the windward edge of the fire.  Yet they found nothing to show them how or where the fire originated.

“Evidently the flames have eaten their way some distance to windward of the point of origin,” said the forester.  “We shall have to look within the burned area.”

As he started to cross the black strip, the forester continued:  “Perhaps I had better go through the burned strip alone.  I want things disturbed as little as possible, and three will stir up the ashes a good deal more than one.  You keep looking along the edge, and I’ll search among the ashes.”

“Is there anything in particular we are to look for?” asked Charley.  “Is there any special way to distinguish the starting-point of the fire?”

“If this blaze started at a camper’s fire, there ought to be some trace of that fire discoverable.  If it began with a lighted match, the stem of that match might not be entirely consumed.  If blazing paper created the fire, there may be a scrap of paper left unburned.  And even the ashes might show that paper had been burned.  That’s why I don’t want the leaves disturbed any more than we can help.  We shall quite likely find our clue, if we find it at all, in the ashes themselves.”

The forester started slowly across the valley.

“I don’t see where he has anything on us as observers,” said Lew.  “If our drill at Camp Brady didn’t make competent observers of us, I don’t know what it did do.  Captain Hardy drilled us and drilled us in noticing even the most minute things.  Let’s go along the line again and look more carefully.  We’ve got a better idea now of what we’re looking for.”