Help for term paper

Hello everybody.

I have to write a term paper where I have to discuss the relationship between appearance and survival in A Tale of Two Cities.
I think this basically concerns the similarity between Darnay and Carton which finally enables Darnay's survival, but I have no idea how to write 15 pages about that. One could perhaps also extend it to say that during the Revolution it was important to appear to be a good citizen if you wanted to survive.
If anyone knows some literature on this special topic I would be very glad if you could tell me.

Thanks a lot, Julia