Remus Lupin

Not necessarily, but the problem is that they have no reason to suspect Mr Finnigan, even if we tried to make it seem he's questionable. He turned in a classmate, which makes him extraordinarily cold even if he didn't know it would lead to such a major breach of the Order's security. If he had been a member of the Order, it would have been far too risky a move to make.

Rookwood's a better candidate to smear, given that he habitually writes to Malfoy in PMs despite Malfoy not having had a journal for months. But he's also enough of a liability for them (for that same reason - hey, I just thought of something. I wonder if we could get Malfoy to read us those messages if we showed him a journal?), that they just might take us up on the deal.

Have to give it more thought.