Bulstrode’s sudden decision to leave Middlemarch was prompted by the return of Raffles on Christmas Eve. Raffles invites himself to stay at Bulstrode’s. As soon as he can, Bulstrode organizes a coach that will take Raffles far away to Isley. He tells Raffles that he will pay him to stay silent, but if Raffles ever shows his face in Middlemarch again Bulstrode will immediately cease all financial support. He says that if Raffles doesn’t leave the house immediately he will call the police. However, even with Raffles gone Bulstrode still feels he can’t stay in Middlemarch, and starts making plans to leave.
Bulstrode’s terror at the consequences of Raffles telling everyone about his past shows how wrongdoing and guilt eat away at a person. Even with Raffles gone, Bulstrode can never feel safe. The burden of his secret and the possibility of it being revealed have become so intense that he has no choice but to flee and try to start life over yet again.
Bulstrode asks Caleb Garth to help him find a tenant for Stone Court, and Caleb suggests Fred Vincy, on the grounds that he could be trusted because Caleb himself would be watching over him. Although Bulstrode is not fond of Fred, he agrees in part to please Caleb and in part to satisfy Mrs. Bulstrode, who wanted her husband to help Rosamond and Lydgate with their debt. Busltrode stresses that he couldn’t help his wife’s married relatives, but that he will do Fred the favor of letting him live in Stone Court. Caleb is thrilled, but keeps the plan secret as a surprise for Fred.
Recall that Mrs. Bulstrode is Fred and Rosamond’s aunt, which is why she (unlike many in Middlemarch) loves the Vincy children and wants to help them. The interconnection of people in the Middlemarch community through blood, marriage, and profession creates a complex web of debts and favors between the characters.