How did Oliver reach Fragin's den and what did he experience there till his arrest?

Oliver is born in a workhouse, to a mother not known to anyone in the town. She dies right after giving birth to him, and he is sent to the parochial orphanage, where he and the other orphans are treated terribly and fed very little. After returning to workhouses and more abuse, Oliver finally runs away. Oliver walks towards London. When he is close, he is so weak he can barely continue, and he meets another boy named Jack Dawkins, or the artful Dodger. The Dodger tells Oliver he can come with him to a place where a gentleman will give him a place to sleep and food, for no rent. Oliver follows, and the Dodger takes him to an apartment in London where he meets Fagin, the aforementioned gentleman, and Oliver is offered a place to stay. Oliver eventually learns that Fagin’s boys are all pickpockets and thieves, but not until he is wrongfully accused of their crime of stealing an old gentleman’s handkerchief. Although full of illegal activities, Oliver finds a sense of place among Fagin and the boys.