I have this memory that it says somewhere that during the First War they suspected a traitor in the Order and it was one of the Marauders and that's why Remus wasn't chosen as Secret Keeper (?). I have a couple of questions on this:

A) Did I completely imagine this or is it real?
B) If real, did it necessarily have to be one of the Marauders, or just someone in the Order?

Mainly my question is if it would be plausible for the Marauders to trust Remus still if, say, the Longbottoms and Dumbledore got killed and they decided to find a new place to hide.

Would be helpful if, in your answer, you provided quotes. I love quotes. I just can't seem to find them. >.<