On the sixth day, a soldier noticed something unusual on the left side of a newly uncovered stone wall.
The stones there were arranged more neatly than those around them, and their edges bore clear signs of deliberate shaping. Together, they formed an outline about the size of an ordinary door.
Soon, under Robb's direction, several soldiers tried prying out a few of the smaller stones.
Behind the stone wall, they discovered a somewhat narrow passage, just wide enough for two people to walk abreast.
Just as Robb was about to send men in to investigate, Benjen's surprised voice came from behind them. "This... this is the Masons' Passage."
At some point, he had come to stand a short distance away. His ice-blue eyes fixed on the pitch-black passage as he said with some excitement, "I can feel it. This leads straight down."
Seeing the puzzled looks Robb and the others gave him, Benjen fell silent for a moment, as though recalling something. Finally, he told Robb, "I remember Maester Luwin mentioning this when we discussed Winterfell's Crypt. It was originally built level by level, and the oldest levels date back to the time of the First Men."
"Some levels were connected by small passages, reserved for the masons who built the tombs. Then the collapses happened. I thought those passages had been blocked off too."
Benjen himself had found it hard to believe. The space beneath the Crypt was enormous, and several levels had been buried entirely, yet this narrow Masons' Passage had somehow remained intact.
In fact, when Winterfell's Crypt was built, the masons had deliberately chosen a solid, unbroken stretch of bedrock through which to cut this passage, then filled every gap with reinforcing mortar mixed with crushed obsidian.
They had done this to leave those entering