So an idea was to do it with particle systems, And so it did. This just one way to do it, maybe there is more.

OK, the first thing was to make two pages animated, one which bend in one corner upwards slow, and the other one the exact move but in reverse and fast.

The second action is to create of course a particle flow system box size with a hight similar to a book, and a deflector, the simple one, large as the particle gismo. Then delete the speed, and rotation operators, add a collision test with the deflector chosen, and a shape instance with the first page picked, the slow one. The deflector has two keys, going up through the pages of the p. system.

Then add a spawn event, which is connected to the collision test and a shape instance with the second page picked.

So the deal is, first the edge of the book is raising due to the animation of the first page, but as the deflector is coming up and collides with every page it finds, the spawn event takes place and the second page is coming out and drops down.

Thats it.

A preview of the animation can be found in the tutorials section in my portfolio