Some creases in the box in the center don't fold flat.

The box-carrying crane flies around carrying a mysterious box on its back. Who knows what’s inside? Perhaps it’s a more advanced delivery crane.

To fold this, I first folded a box in the center of the crane, using the \(\tan^{-1}(1/2)\) gadget found in this paper. Then I folded a crane around it. Folding a crane around something sticking out is not trivial, however, as you’re not allowed to flatten the model. This required some air folding.