(I'm alive - and found this topic while searching for another old one!)
So... now I can only think of
The regent's daughter by Alexandre Dumas. The entire book is very exciting:
Spoiler Below We have four people conspiring to kill the regent, while one of them, Gaston, is in love with Cecile, who is - unbeknownst to all - said regent's daughter. The regent discovers everything and comes to like Gaston, and in the end forgives him and wants to let him marry his daughter. Happy ending, you'd think. Well, nope. The other three conspirators have been caught and ready to be executed, and what does Gaston do? A sane person would marry Cecile. But no, he gives himself up and gets executed too, then Cecile dies of sadness and the regent too.
It sucked so badly, I didn't read more Dumas after it.