In chapter 39, chow does the convict's statements build tention?

The convict's statements provide tension, because unlike their meeting in Chapter One, Pip is unaware of who has come to see him. Magwitch's revelations change Pip's life again. First you have the innuendo they've known each other before, the allusions the Magwitch knows something Pip does not. Then you have the revelation, which leave Pip reeling. He's spent years wrongly assuming someone else to be his benefactor, and yet his benefactor got exactly what he didn't want. Pip's attainment on "gentleman" status had changed him drastically........ whereas Magwitch's desire was that he never change.