She was not in favour of hustling priests when they took the trouble to call, for at times there was a little money to be got from them.

And when she realised that Salvat, who had once more relapsed into his black reverie, left her free to act as she pleased, she at once tendered her services.
"If Monsieur l'Abbe is agreeable, I will conduct him.

It's just at the end of the passage.

But one must know the way, for there are still some steps to climb." Celine, finding a pastime in this visit, escaped from her father's knees and likewise accompanied the priest.

And Salvat remained alone in that den of poverty and suffering, injustice and anger, without a fire, without bread, haunted by his burning dream, his eyes again fixed upon his bag, as if there, among his tools, he possessed the wherewithal to heal the ailing world.
It indeed proved necessary to climb a few more steps; and then, following Madame Theodore and Celine, Pierre found himself in a kind of narrow garret under the roof, a loft a few yards square, where one could not stand erect.