 that's going to hit these mirrors, because if you're going to use lasers in the body, you need to be able to direct it there. So our hope is to direct it there with optical fibres, but if you didn't have an optical fibre, you'd have to use a bunch of mirrors and lenses and stuff, which you can imagine would be quite hard, which is the game. So I should explain, it's like a table with a glass top to it. Then there are these six mirrors, three on each side, and then there are various obstacles in a way, like little film boxes, little cylinders, and then there's a brain at the end that you've got to get to. And then there's these buttons.