For me, the hump comes right around the middle of my wip. I don't know why. I have a feeling that it has something to do with the moment when something is getting ready to change. When a twist or turn arrives. Just when something happens in the middle of your wip. It's dramatic. It's powerful.
Let's face it ... it's hard.
And that's where I get stuck. It's happened with all three of my books. I've stopped--almost dead center (or 3/4 of the way through)--and had to literally PUSH my way through five chapters or so (hence the name).
When I reach the hump--everything stops. The plot, the momentum, the drive (that's the worst). And it lingers. I can't get away from it, and I can't really walk away.
It's painful to face the hump. Don't confuse the hump with writers block. It's not the same thing. I've only had writers block once and that was because of stress. The hump is different. You're a peak of your story, your mind is going in a million different directions. You're confused. You're scared. You're uncertain of what to do next ... but the ideas ARE there.
Sometimes the hump lasted a few weeks (like book #2), sometimes a month (like book #1), and sometimes...it lasted A LOT longer. Book #3 had a six month hump. Granted, the book itself wasn't the only problem. I had also been stuck in editing hell.
How do I get over the hump? Once I actually stopped writing and did somethng else all together (rewrite nightmare, anyone?) The other times I pushed myself through it. I sludged. I painfully worked my way through the problem until I thought my eyes would bleed.
And then? Whoa! Watch out! After I get over the hump, the book is done in a matter of days. Okay, maybe not days ... sometimes weeks. The point is, once I'm over the hump, I fly to finish line.
I'm scared of the hump. Every time I write a new book I think ahead and I know its coming. I'm just not sure when. Watch out for the hump. And above all--don't let it stop you!