In Harry Potter and the Prisoner of Azkaban chapter 19, when Peter Pettigrew is in a really tight situation, he is pleading to Remus Lupin this way.

‘Remus!’ Pettigrew squeaked, turning to Lupin instead, writhing imploringly in front of him. ‘You don't believe this … Wouldn't Sirius have told you they'd changed the plan?’

‘Not if he thought I was the spy, Peter,’ said Lupin. ‘I assume that's why you didn't tell me, Sirius?’ he said casually over Pettigrew's head.

‘Forgive me, Remus,’ said Black.

‘Not at all, Padfoot, old friend,’ said Lupin, who was now rolling up his sleeves.

(In that conversation changing the plan refers to using Peter as the Secret-Kepper instead of Sirius.)

Had Sirius really believed at some point that Lupin was the spy? Was Lupin suggesting it seriously that Sirius would believe that?

I have the impression that neither of them actually thought that. Lupin had been convinced that Peter was guilty from the point when he saw him in the map, and at this point they managed to convince Harry as well. Lupin may have had enough of Peter's pointless objections and wanted to get over with this conversation as fast as possible, which is why he said this, and Sirius went along. But other readers didn't seem to have perceived the dialog that way. What's the truth?

  • 2
    more like 'we don't know who to trust, the fewer people who know the better' – Wraith Leader Aug 16 '17 at 17:49
  • 1
    Lupin was talking about 1980 - when everyone thought Sirius would be secret keeper. Instead, the Potters flipped the script and made Peter secret keeper. Sirius obviously knew they did that, but just in case, he didn't tell anyone else – NKCampbell Aug 16 '17 at 18:15
  • @NKCampbell Yes, of course. After that, Sirius was in prison, there was no more chance he could tell Lupin anything. – b_jonas Aug 16 '17 at 18:30

It was easier to suspect Lupin the Werewolf than to suspect Peter the Coward. Lupin had more reason to be bitter about his life and turn traitor rather than Peter. Besides, Voldemort would have valued Lupin more than Peter if he had joined.

  • 1
    @MrRiddle That argument works for an external observer, but may not be enough for Sirius, who was Lupin's friend. – b_jonas Aug 16 '17 at 18:29

Not the answer you're looking for? Browse other questions tagged or ask your own question.