As Jane prepares to leave to go to Thornfield, St. John slips a note under her door urging her to resist temptation. Though unsure herself, Jane feels that what's she's doing is right and that the voice and the "wondrous shock of feeling" she felt were real.
St. John thinks that all feeling is wrong. He does not value passion or human love. But Jane, while herself unsure, still believes in it.
On the journey to Thornfield, Jane thinks about the differences the year away has made in her. Formerly poor and alone, she now has a family and a fortune.
Jane used to be dependent on Rochester for family and money. Now she returns to him for love, and is independent.
At Thornfield, though, Jane is astonished to find the house burned down and in ruins.
Jane's dreams in Chapter 25 foreshadowed this destruction.
Jane learns what happened from the proprietor of a local inn. Bertha escaped and set Jane's old bedroom on fire. As the inferno spread, Rochester helped all the servants get out safely. But he could not save Bertha, who stood on the roof laughing maniacally and then jumped to her death. In the collapsing building, Rochester was badly injured: he lost a hand and lost his sight. He lives nearby in a modest house called Ferndean.
Bertha uses fire to destroy the room where Jane, who stole Bertha's husband's love, lived. Fire symbolizes Bertha's unrestrained passions and madness. The inferno represents the fatal consequences of Rochester's secrets. He loses his eyes, symbols of his pride and power, as punishment from God.