predicament of pip in the novel of great expectations

Magwitch has come to visit him and reveals that he is Pip's benefactor,then Herbert goes into the apartment.  Pip informs Herbert and they must decide how they must ensure some lodging for the old convict.  After Magwitch leaves, Pip and Herbert both quiver at the strangeness of the man for , when Herbert sits in the chair that Magwitch has just occupied, he "next moment started out of it, pushed it away, and took another." Of course, Pip is disguested that such a disreputable person is his benefactor when he has believed all along that Miss Havisham has been this person.