In my story, Regrets , Hermione doesn't realize that she saw the instructions for a certain potion that Voldemort desperately wants to brew in order to take down the Order of the Phoenix and end the war once and for all.
Voldemort thinks she has the information but doesn't know for sure, and is going to send Peter in to try and retrieve it from her. Voldemort knows that force is not going to accomplish his goal, so he is going to try finesse. Believing that Snape has built up at least a minor rapport with Hermione during their time in the cottage, and even while trying to keep her off balance by making her think that Snape still works for the side of evil, Peter is going to be polyjuiced into Snape and sent back in.
I need assistance with how Peter would portray Snape. I need a well-rounded view, from anger to attempts at coercion. I will also have Hermione figuring it out in the end, just before Peter leaves the cottage. I was thinking maybe a tic, like Barty Crouch Jr’s tongue thing. Maybe Peter could have a rat-like nose twitch or something like that. Something that Snape would obviously not have, that could give the deception away.
I hope that I am posting this in the right place now, since I was told that I posted in the wrong place when I had it in Skele-Gro Plot Potion.