Describe the preparations that Pip and Herbert make to save Magwitch. How does the plan fail?

After being warned that an old enemy (the other escapee at the beginning of the film) knows that Magwitch is in London, Pip makes preparations to smuggle the old man onto a packet boat and accompany him to the continent. Pip, Herbert and Magwitch row out to the packet boat, but are intercepted by the waiting police, tipped off by Magwitch's great enemy. Magwitch is seriously injured in a struggle with his nemesis. He had spoken to Pip of his lost daughter, and Pip's suspicion that she is Estella is confirmed by Mr. Jaggers. Pip visits the dying Magwitch and tells him of her fate, and that he, Pip, is in love with her; Magwitch passes away, a contented man.

Pip has made plans for Magwitch's escape, but he needs to get him downriver to a German steamer that will take both of them away. They had almost reached the ship when a rowboat showed up with a policeman and Compeyson. The men have been betrayed, Magwitch dives into the river after Compeyson, and then he's arrested for the man's murder (Compeyson never surfaces).