How to do hover/shade roll-up effect?

How to do hover/shade roll-up effect?

I found a few sites that do what I'm looking for, but I'm not sure how to implement. I'm looking to show an image with a caption, then when the user hovers over it, for a block of text to roll-up in front of it like a shade effect.

This page shows what I'm looking for:


Would this require a plugin or is this fairly straight-forward to implement? Or, if anyone knows of a jquery plugin that might do the trick. 

Thanks!