Jane has agreed to marry Mr Rochester, despite the fact that they have such a big age difference and they are also in different social classes. Mr Rochester wants the wedding to commence quickly.
When the priest asks if anyone objects to the ceremony, Mr Briggs objects and tries to stop the marriage. Rochester attempts to proceed with the ceremony, but Mr Briggs explains that Rochester was already married to a woman called Bertha Mason 15 years ago!
Mr Rochester gets really mad and then Richard Mason, Bertha's brother, steps forward to corroborate the story. After a moment of inarticulate anger, Mr Rochester finally admits that his wife is alive and also tells them that he has kept her locked away in Thornfield Hall.