The Thief Lord by Cornelia Funke

The three boys moved hesitantly down the wide center aisle, their steps ringing out on the flagstone floor.1 The golden domes that arched above their heads kept their splendor hidden in the gloom, and in between the tall marble pillars that supported them the boys felt as small as insects. Instinctively, they moved closer together.

“Where are the confessionals?” Mosca whispered, looking uneasily around him. “I haven’t been in here very often. I don’t like churches. They’re creepy.”

“I know they are,” Scipio replied. He pushed the mask back onto his face and led the way as purposefully as one of the Basilica’s tourist guides. The confessionals were tucked away in one of the side aisles. The first one on the left looked no different from the others. It was a tall box made from black wood, draped with dark red curtains and with a door in the middle2, which the priest used for slipping into the tiny space behind. Inside, he would sit down on a narrow bench, put his ear to a small window, and listen to all who wanted to tell him their sins and clear their conscience.3

Of course there was also a curtain on the side of the confessional to protect the sinners from curious eyes. Scipio now pushed this curtain aside, adjusting his mask one last time and clearing his throat nervously. The Thief Lord tried very hard to pretend that he was coolness itself,4 but Prosper and Mosca, as they followed him behind the curtain,5 sensed that his heart was beating just as fast as theirs.

Scipio hesitated as his eye fell on the low bench half hidden in the darkness, but then he kneeled down on it. The small window was now level with his eyes and he could be seen by whoever sat on the other side. Prosper and Mosca stood behind him like bodyguards. Scipio just knelt there, waiting.6

[Source]