This puzzles starts with three sheets some distance apart. Draw bands between the sheets, then wiggle to pull them together. The goal is to make as many hydrogen bonds between the sheets as possible.
Madde's "Sheets and Ladders" video
Loci's "Sheets and Ladders" video
About three bands between each pair of sheets should be enough.
You'll notice there are blue dots and red dots along the edges of the sheets. The blue dots can form hydrogen bonds with the red dots. Also, the red dots are on "hills" and the blue dots are in "valleys". The hills and valleys should fit together.
After wiggle, try shake for a few extra points. Delete the bands, then wiggle and shake again for even more points.
Technical stuff: notice that the sheets in this puzzle aren't flat like the ones in the first couple of puzzles. Welcome to real life. Nothing is very flat or straight in the protein world.