Your spouse asks you for a divorce, and you count your lucky stars that you have a prenuptial agreement. At least your financial assets are protected, right?
Maybe, but it could turn out that your prenup is useless. If it doesn't hold up in court, the judge can throw it out and then nothing that you agreed to is going to help you.
Now, this can just apply to certain issues. For instance, maybe you put into your prenup that you would never have to pay any child support. You can't do that, and the court is going to order you to pay child support if it's reasonable, regardless of the prenup.
But there are some things that can make the entire prenup invalid. One is signing it at the so-called "eleventh hour." This is a general term, of course, just meaning that the wedding is right around the corner. If the court decides that it was signed too near to the wedding, they could toss out the entire prenup, even if everything else is in order.
Why do they do this? Basically, your spouse can't sign under duress and must have time to consider the ramifications of the prenup careful. In this case, they could argue that they certainly didn't have time to think about it and that the approaching deadline -- the wedding itself -- made it so they were under duress while they signed.
As you can see, divorce laws are often a bit more complicated than they first appear, and it's important to work with an experienced legal team to avoid mistakes.