About half way solved.
Detail of Maple and Wenge miter.
A corner after a few moves.
42 move Waterfall Box
A very elegant sequence of 42 movements is required to unlock this box. Each side moves according to a 3x3 maze hidden beneath the moving plate. For example, an individual plate plate may move up. left, then down, then right. The plates overlap each other at the edges. So in order move one side, you will have to move the plate blocking it first.
This Waterfall takes the same appearance as the previous Waterfalls, but it is engineered with more strength. The plates are nearly twice as thick as the previous Waterfalls. There is also a considerable amount of concealed joinery keeping the wenge and maple stripes strongly intact. I have also re-engineered a type of double-action sliding dovetail, which can be made from one piece of wood. This generates the most wonderful movement regardless of humidity changes.
The Waterfall series is five boxes. Each successive box requires more moves to open. When the first four boxes are combined in a certain way you will have clues to opening the fifth box.