I know Debra went off the cliff in S6, I haven't seen S6. The last scene I saw was Debra walking in on Dexter carving up a body - she was about to confess she was in love with him.

Then I read the spoilers that she aids and abetts him, and kills La Guardia to save him. And I thought, damn. Not sure I want to see that or the destruction of her career for her brother.