Harry Potter and the Chamber of Secrets (novel)/Tear Jerker

Tear Jerkers in  include:

""Prongs rode again last night.""
 * When Harry realizes what his Patronus is.


 * Harry's learning of the Patronus (or rather, his initial struggle to do so) is sad in a way that's so obvious that it's almost subtle. Especially the film, where Harry fails the first time and Lupin asks him what happy memory he chose to try to power the Patronus. Harry responds with his first memory of riding a broomstick and Lupin says that it wasn't "nearly strong enough." But until Harry finds the loophole (the memory doesn't always have to be real - it can be a positive hope or dream or the like), that's literally the best he can come up with up to that point. :'(
 * A rather subtle, but effective, moment comes in Prisoner of Azkaban when Harry catches himself half-hoping to be overwhelmed by a Dementor since, horrible as the experience is, it's the only time he's ever heard his parent's voices.