Split posts into multiple chunks/sections

Hi all I was hoping someone could help me with a element of a theme I am working on for a political news site I am working on powered by WP.

What I would like to achieve is the following:

A masonry homepage powered by masonry.desandro.com – This I have done

The hard part for me is displaying the post like I imagine and could do with help on.

I basically want to chunk the story with the latest short update at the top, then the user can scroll down to see previous updates of the post.

If anyone can help with this that would be great.