double nugget switch-a-roo

Usually performed inside of school, secretly take someones backpack and empty all of the books out of it. Take someone else's backpack and take the books out of it again. Flip both backpacks inside out. Take the books to the first backpack and place them in the second bacpack. Also, take the books of the second backpack and put them in the first back pack. Then, zip them up and return them to their original owners.