After Eponine dies, Marius gently kisses her on the forehead as he has promised. He enters the inn to open the letter she has given him, for he feels the impropriety of reading it beside her body. It is a note from Cosette informing him of her departure from the Rue Plumet. He is momentarily elated by this proof of love, but only momentarily since the possibility of their marriage remains as remote as ever. He resigns himself once more to death and makes his last dispositions. He writes a note to Cosette to be delivered by Gavroche. This way he will kill two birds with one stone: assure his sweetheart of his love and save the urchin. Then he leaves instructions to have his body delivered to his grandfather.
Gavroche, afraid he will miss the great encounter, is reluctant to accept the errand. He undertakes it only because he intends to return immediately rather than wait until the next day as Marius has suggested.
On June 4, just before the insurrection, Valjean moves to his retreat in the Rue de l'Homme Armé. So deep is his alarm that he overrides Cosette's unprecedented objections. Once installed in his new quarters, he feels reassured, for the Rue de l'Homme Armé is located in an obscure and neglected neighborhood. Cosette, on the other hand, is deeply distraught. She spends the day in her room and appears only for dinner. Then, pleading a headache, she leaves the table.
Cosette's chagrin does not disturb Valjean's tranquility. He is in an optimistic mood and has radiant visions of renewed happiness in England. A heartbreaking discovery shatters his dream. On the table there is a mirror that reflects Cosette's blotter and rights its inverted message: Cosette's letter to Marius. At first, Valjean refuses to accept the evidence, but the message remains inexorably in the mirror.
