Loading more than one random clip?

Heres the deal. I’ve found tutorials that show how to randomly load from a selection of movie clips. My problem is, I have two clips that load on top of each other. Ones a blurred image, the other is a clear, and when you move a mask over the image, it goes from blurry to clear. Right?

But I want a different image to load everytime. Problem is that I need both the random blurry and clear pictures to be the same! No point moving your mouse over a blurred picture of a mountain only to find a clear river underneath, right?