during the German siege. He remembered the big cannon up on the hill, and the fighting over them, and the terrible shooting of Communards when the government troops arrived from Versailles. His father had been careful to stay out of trouble—or perhaps he was just too lazy—but like most workingmen, he had no liking for this vast, triumphant monument to Catholic order that the conservative new republic was placing on the hill to stare over the city. Thomas, however, had been fascinated: not by the church’s meaning, but by how the huge thing was built.
And for that reason, as he gazed at the sacred site on the hill of Montmartre, he began to feel a sense of dread.
The hill was mainly composed of the soft stone material known as gypsum, which possessed two qualities. First, it would slowly dissolve in water, and was thus a poor foundation for any large building. Second, when heated, after giving off steam, it could easily be ground to the powder from which white plaster was made. For that reason, men had been burrowing into the hill of Montmartre for centuries to extract the gypsum. And so famous had these quarryings become that now, even across the oceans, white plaster had come to be known as plaster of Paris.
When the builders of Sacré Coeur began their task, therefore, they found that the underlying terrain was not only soft, but so honeycombed with mine shafts and tunnels that, had the great building been placed directly upon it, the entire hill would surely have collapsed, leaving the church in a stupendous sinkhole.
The solution had been very French: a combination of elegant logic and vast ambition. Eighty-three gigantic shafts were dug, each over a hundred feet deep, filled with concrete. Upon these mighty columns, like a huge box almost as deep as the church above, the crypt was constructed as a platform. This work alone had taken almost a decade, and by the end of it, even those who hated the project would remark with wry amusement: “Montmartre isn’t holding up the church. It’s the church that’s holding up Montmartre.”
Every week, Thomas had gone to the site to gaze. Sometimes a friendly workman would take him to see the cavernous excavations and giant masonry up close. Even when the work on the church itself had begun, the site was still a muddy mess, cratered with pits and trenches. And now, as he stared at the high boards of the fence, the thought came to him, with a horrible urgency: What if his poor little brother’s body had been dumped somewhere on that site? It might be days before it was noticed, if it hadn’t already been covered over. Or what if it had been dragged into the maze of tunnels and shafts below? There were ways into that labyrinth, but once inside it was easy to get lost. Was Luc down there, in the dark and secret chambers of the hill?
No, he told himself, no. He mustn’t think like this. Luc was alive. Just waiting to be found. All he had to do was think. Where might he be?
He walked forward to the corner of the street below and paused. All Paris lay before him. Here and there a golden dome could be seen, or a church steeple rising above the rooftops. On the main island in the Seine, the towers of Notre Dame Cathedral rose higher than all. And above them, the blue sky still reigned, uninterrupted. And telling him nothing.
He tried to pray. But God and His angels were silent as well.
So after a while, he started along the street that led westward along the contour of the hill. There were some houses here, of the better sort, with small gardens. The lane began to descend. On his right a steep bank of land appeared, with a garden wall above it. The bank was covered with bushes.
“Psst. Thomas.” A whisper from above. He stopped. His heart leaped.He looked up into the bushes. He couldn’t see anyone. “Are you alone? Is anybody in the lane?” It was Luc’s voice.
“Nobody,” said Thomas.
“I’m coming down.” Moments later, Luc was at his side.
They both had