Writer's Block

Yes, the dreaded writer's block has befallen me. It sucks. I'm working on the third book of my Evil trilogy, and I'm stuck. I know how it ends, and I have my pre-written rough sketch written. I'm mostly satisfied with the first twenty pages. I know some of the parts in the middle. I know the arc that gets my character, Rebekah, to the final situation. But there's all this other stuff that needs to be in the book, and I don't know what it is. Did I say that this sucks? I'm going to have to get out index cards, I think, and write a scene summary on each card, put them in order, and see what I have. And then make new scenes and put them in order. Just writing about writer's block has made me think of two scenes for the book. And then I went away and roughly outlined the rest of the book. Maybe I'm not so blocked after all.