Trotter struck a match and lighted his candle. He waited without moving for the flame to grow. Then he thrust the candle up before him. As he did so, his hand came in contact with the rough surface of what at first he took to be a stone wall. But as he looked closer he saw that it was not masonry. It was nothing more nor less than a carefully piled mass of stone and brick. Each fragment had been carefully placed on top of its fellow, each interstice had been carefully filled with rubble.
The pile extended from floor to ceiling. It filled the entire cellar. It left only space enough for a man to pass inward from the opened door. It was nothing more than the dump of a mine, the rock and brick from a tunnel, not flung loosely about, but scrupulously stowed away.
Holding the candle in front of him, Trotter bent low and groped his way in through the narrow passage. Everything was as orderly and hidden as the approach to a wild animal's lair. Everything was eloquent of a keen secretiveness. No betraying litter met his eye. Each move had been calmly and cautiously made. Each step of a complicated campaign had been quietly engineered. Trotter could even decipher a series of electric wires festooned from the little tunnel's top. He could see where the passage had gone around obstacles, where it had curled about a dishearteningly heavy buttress base, where it had dipped lower to underrun a cement vault bed, where it had sheered off from the tin-foiled surface of a "closed-curcuit" protective system, and where it had dipped and twisted about to advance squarely into a second blind wall at right angles to the first.
A portion of this wall had been torn away. With equal care an inner coating of cement had been chiseled off, exposing to view an unbroken dark surface.
As Trotter held the candle closer, he could see this dark surface marked off with chalk lines, sometimes with crosses, sometimes with figures he could not decipher. On it, too, he could see a solitary depression, as round and bright as a silver coin, as though a diamond drill had been testing the barrier.
He knew, even before he touched the chill surface with his hand, that it was a wall of solid steel, that it was the steel of the bank vault itself, the one deep-hidden and masonry-embedded area which stood without its ever-vigilant closed-circuit sentry. And he knew that Heeney had grubbed and eaten and burrowed his way, like a woodchuck, to the very heart of the First National Trust's wealth.
It was only then that the stupendousness of the whole thing came home to Trotter. It was only then that he realized the almost superhuman cunning and pertinacity in this guileless-eyed cellar plotter called Heeney. He could see the hours of patient labor it had involved, the days and days of mole-like tunneling, the weeks and weeks of gnome-like burrowing and carrying and twisting and loosening and piling, the months of ant-like industry which one blow of the Law's heel would make as nothing.
It rather bewildered Trotter. It filled him with an ever-increasing passion to get away from the place, to escape while he still had a chance. It turned the gaseous underground tunnel into a stifling pit, making his breath come in short and wheezing gasps. It brought a tiny-beaded sweat out on his chilled body.
Then he stopped breathing altogether. He wheeled about and suddenly brought his thumb and forefinger together on the candle flame, pinching it out as one might pinch the life out of a moth.
For on his straining ears fell the sound of a door slammed shut. There was no mistake, no illusion about it. Some one had entered the shop. Then came the sound of a second door. This time it was being opened. And it was the door leading into the tunnel.