Great Expectations Chapter 47: I Go to the Play...
Weeks pass without incident; Pip continues rowing every day, and also, with some satisfaction, declines to take any more money from Magwitch. He decides to pass one evening at another of Wopsle's dreadful performances, where he is particularly disturbed when Wopsle turns all of his attention to him at one moment in the performance, his face showing an odd shock of recognition. After the show, Wopsle finds Pip and explains that he saw a ghostly figure sitting behind him in the audience, and that he recognized the face as that of one of the convicts they'd seen in the marshes many years back. Pip now has his first evidence that Compeyson is on his trail.
Pip returns to the Temple and tells Herbert about being followed. The two agree that Pip must be particularly cautious, and they post a letter to Wemmick that says Compeyson has been sighted. Pip tells Wemmick to let him know immediately if anything new develops.