Book 3: The House On The Rue Plumet
Sketching Les Mis Chapter 4.3.1 - The Secret House
So, it turns out, Monsieur Leblanc is Jean Valjean? All this time? What
He left the convent with Cosette after five years when old Fauchelevant died ( :(((( ). He payed the convent five thousand francs for Cosette's education. It was for a number of reasons but mostly because he was happy there but felt he was stealing Cosette's life to be happy himself. So he bought three different places in Paris, two apartments and one house. He didn't feel like he was in too much danger of being caught anymore, but kept these just in case.
The place at Rue Plumet was built by a judge to house his mistress, and features all the sneaky necessities of a man with a secret: a garden with plants that hide the main house, a second building with two rooms in the back, and a winding secret passage that leads from another street into the back building. It was used by the judge to come in, but could be used by someone who wants to leave without being seen.
EDIT oh also! Valjean keeps the box with him still! the box with little Cosette's clothes! and the key with him at all times! I am emotional over that stupid box