The Lion and the Serpent

AU. She is a Pureblood Slytherin wanting to break free from the constraints of her upbringing and he is a Gryffindor rebel who has already accomplished what she could only ever dream of. She desperately needs his help, but will he consent to giving it to the uncrowned princess of the rival House? After all, there's always a price to pay, even - or especially - for kindness.