You certainly didn't ask him for advice on your Theft.
Eric was still brooding on the unprecedented nature of his uncle's instructions when they came to the end of their journey, a large, blind-alley burrow. There was a line cut deep into the blank wall here, a line that started at the floor, went up almost to the height of a man's head, and then curved down to the floor again.
The door to Monster territory.
Thomas the Trap-Smasher waited for a moment, listening. When his experienced ears had detected no unusual noises in the neighborhood, no hint of danger on the other side, he cupped his hands around his mouth, faced back the way he had come, and softly gave the ululating recognition-call of the band. The four other warriors and the apprentice came up swiftly and grouped themselves about him. Then, at a signal from their leader, all squatted near the door.
They ate first, rapidly and silently, removing from their knapsacks handfuls of food that the women had prepared for them and stuffing their mouths full, the beams from the glow lamps above their eyes darting incessantly back and forth along the arched, empty corridor. This was the place of ultimate, awful danger. This was the place where anything might happen.
Eric ate most sparingly of all as was correct for an initiate about to emerge upon his Theft. He knew he had to keep his springiness of body and watchfulness of mind at their highest possible pitch. He saw his uncle nodding approvingly as he returned the bulk of his food to the knapsack.
The floor vibrated slightly underfoot; there was a regular, rhythmic gurgling. Eric knew that meant they were directly over a length of Monster plumbing: upon his return, before the band started homewards, Thomas the Trap-Smasher would make an opening in the plumbing and they would refill their canteens. The water here, nearest to Monster territory, was always the sweetest and best.
Now his uncle got to his feet and called Roy the Runner to him. While the other warriors watched, tense and still, the two men walked to the curved line and laid their ears against it. Satisfied, finally, they inserted spear points into the door's outline on either side and carefully pried the slab back toward them. They laid it on the floor of the corridor, very gently.
A shimmering blur of pure whiteness appeared where the door had been.