Not necessarily. We could be offering to trade him for someone we want dead. We could implicate someone we want them to distrust by demanding them. We could confuse them immensely by demanding Maghnus Derrick.
His point was, it wouldn't work. So it doesn't matter who we want; the question is, who is it to our advantage to ask for.
Re: Private Message to Remus
His point was, it wouldn't work. So it doesn't matter who we want; the question is, who is it to our advantage to ask for.