An impossible possibility!
If you are a fan of the classic Sawing-In-Half Illusion or the Zig Zag Girl Illusion or the Blade Cabinet Illusion, you'll love this one!
Start with the empty wood tube. Notice that it has holes in it, so you can see what is inside at all times.
Place the two blades through the tube. Your audience can clearly see the blades go through.
Now the middle of the tube is blocked by the blades.
Take the yellow block, and drop it into the tube.
Your audience will be able to see the yellow block as it VISIBLY PENETRATES right through the blades!
At the end, you show the empty tube, the block and the blades.