This is my first instructable so bare with me. Feedback is greatly appreciated both positive and negative.

The puzzle box is a mystery box that can only be opened once you pull out the lock key and then both adjacent corners have to be grabbed in order to open.

It will take them awhile even if they get the lock key out because they still have one more step to open it. Which experience shows that grabbing the corners is the trickiest part. The puzzle box will keep your nosey siblings and parents out and even the amateur thief.

Step 1: What You Will Need

Materials:
6" x (1/4)" x 48" pine plank. I found mine at the local lumber yard
Wood glue
Finishing nails
(1/4)" wooden dowel

Tools:
Saw: Table saw, miter box saw and band saw will help you out greatly

Hammer: to pound in the nails of course

Drill and .25" wood bit

Step 2: Making the Outer Box

Cut 2 pieces 3.5" x 7" (top and bottom)
2 pieces 1.5" x 7" (sides)
I piece 1.5" x 3" (back)

Lower your table saw to a height of (1/8)" inch and cut a grove 1.25" from each side of the top and bottom piece.

On the top and bottom pieces cut a a square (1" up and all the way to the grove) out of a corner. Make sure that they are cut out of same corner. Save the pieces you cut off.

Now you can assemble the box together and make sure not to nail in the middle of the box or the nail will get in the way when you drill your holes.

Step 3: Making the Drawer

Cut 2 pieces 1.25" x 6.25" (sides)
2 pieces 1.5" x 3" (front and back)
1 piece 3" x 6.25" (bottom)

Once you have assembled the drawer make sure it fits into the outer box or some sanding may be required to get a snug fit.

Put the drawer in the outer box and glue the two pieces onto the drawer and make it look like you didn't cut them out.

Step 4: Adding Strips and Lock Key

Once your glue is done drying mark all sides 1" from both ends and one in the middle (3.5") . Then cut 6- 4" x .75" and 6- 2" x .75" wood strips and glue all of them but one of the short middle ones. Having the line be in the middle of the strips.

Next drill (making sure your drawer is in the box) two .25" holes .75" from each side where you didn't glue the strips. Then drill half way through the strip you didn't glue on and and glue your dowel (about .75" long) in the holes.

Step 5: Finishing Up

To make it look better and take away all your imperfections and make the cuts less noticeable give your box a dark stain or burn finish.

Then stash all your valuables in the box and only you will know how to open it. Enjoy!