secrets of hot jude law wizard

The more I try to remember something that happened in the movie I get more confused, if that's even humanly possible.

And what even was the secret? His feelings for Grindelwald? That blood pact thing? The fact that he was apparently pure of heart? As if he wasn't ready to rain fire on the world of muggles a few decades back.

I really should've finished that damn film. Maybe, I will. Once school boils over.