Left alone, Gus crept nearer the cabin.  He could be reasonably sure of himself, but not of Bennie, who might crack a stick or sneeze.  Some low cedars grew on the slope above the cabin; Gus took advantage of these and got within about forty feet of the shack.  Then he lay watching for fully an hour, there being no sign of the inmate.  But after what had seemed to Gus almost half the night, out came the suspect, stood a moment as before and started off; it could be seen that he carried a small pack and a heavy stick in his hands.

Then Gus was taken by surprise; even his ready intuition failed him.  He had made up his mind that he was in for a long hike to the not too distant mountains and that over this ground the work of keeping the other fellow in sight and of keeping out of sight himself was going to mean constant vigilance and keen stalking.  But the midnight prowler swung around the cabin and with long, certain strides headed straight for the Hooper mansion.

This was easier going for Gus than the open road toward the mountains would have been; there was plenty of growth—­long grass, trees and bushes—­to keep between him and the other who never tried to seek shelter, nor hardly once looked behind him until the end of the broad driveway was reached.

Gus knew the watchman must be about, though possibly half asleep.  He also believed that the suspected youth, by the way he advanced, must know the ways of the watchman.  Roger, the big Saint Bernard, let out a booming roar and came bounding down the driveway; the fellow spoke to him and that was all there was to that.  Gus stayed well behind, fearing the friendly beast might come to him also and thus give his presence away, but Roger was evidently coaxed to remain with the first comer.

The big house stood silent, bathed in the moonlight; there was no sign of anyone about, other than the miscreant who stood now in the shadow, surveying the place.  Presently he put down his pack, went to a window and, quick and silent as an expert burglar, jimmied the sash.  There was only one sudden, sharp snap of the breaking sash bolt and in a moment the fellow had vanished within the darkness and Gus distinguished only the occasional flash of a pocket torch inside.

There was but one thing to do, and that as quickly as possible.  The dog had gone around to lie again on the front veranda.  Gus made a bolt for the rear of the grounds, reached the garage, found an open door, began softly to push it open and suddenly found himself staring into the muzzle of a revolver that protruded from the blackness beyond.

“Don’t shoot!  I’m Gus Grier, Mr. Watchman.”  The boy was conscious of a certain unsteadiness in his own voice.

“Oh!  An’ phwat air yes doin’ here?”

“Talk low,” said Gus, “but listen first:  There’s a burglar in the house.  I spotted him some time ago, followed him and saw him get through the dining-room window.  Move fast and he’s yours!”