This mystery box is a wooden cube with no apparent way of opening it. On one side there is clearly a square cut into it, but there is no latch, no knob, and no keyhole to try and open it with.

Mystery boxes, how do they freakin' work?

Step 1: Supplies

Here's what you need to make this
- 1/4" plywood
- Elmer's Carpenter's Wood Glue
- magnetic childproofing lock
- black spray paint (optional)
- laser cutter (optional)
- wood saws (optional)
- clamps
- drill press

For this project, I made all the cuts with a laser cutter. This made the interlocking edges a lot easier to pull off, but those edges are completely optional. Make the box any way you want and decorate it any way you want. The big trick is with the magnetic locks.

Step 2: Cut, Cut, and Paint

All of these pieces were cut with a laser cutter. In addition to the cuts, I also used the laser cutter to cut away at some masking tape I had laid on top of the wood. By peeling off the positive parts of the image, I was able to create a stencil that I could use to apply the designs with the black spray paint.

The files needed are below.

Step 3: Gluing and Clamping

For the sides and top pieces it was just a matter of applying the Elmer's Carpenter's Wood Glue to the sides, attaching it all together. and clamping it. It's pretty straightforward. I did this in 2 steps, though. I first glued the sides in place with the top piece to register it and then glued the top to the rest separately.

The more complicated part here involved the bottom piece. Here you can see the extra layers of wood on the piece and the side that all needed to be glued together in order for it to work.

Step 4: Attaching the Latches

Now that the bottom piece has all the wood in place, it's time to attach the latches. Here I used a 1/4" drill bit to drill out the holes for the bottom piece of the latch. I used a bigger bit than I needed so that there would be a little bit of wiggle room for adjusting the placement of the latch.

I put a little bit of hot glue inside the two holes and placed the latches in it. Now I put the whole thing together and moved the latches into just the right place so that the latches would keep the middle piece of wood as flush as possible with the rest of the side of the cube.

When you're totally happy with the special side of the sube, glue it to the rest of the box.

Step 5: Put in Something Special

Now it's time to put the box to work. Put in a present or a special message for a friend and see them try to get it out. Feel free to give whatever hints you want along the way.

Enjoy!