You found this thing just lying in a box on the street; honestly, you're not sure what on Earth it is, and the waterstained and photocopied pages that came with it weren't much help. As far as you can gather, the user puts on the headset, affixes the electrodes to their face, and pushes one (and only one) of the nine buttons, each one labeled with its own peculiar symbol.

If anybody had asked you yesterday morning if you'd be sitting here with a gadget you can't positively identify strapped to your head preparing to press a button of unknown function, you'd have laughed in their face. Or at the very least, given them a very peculiar stare. But then, yesterday morning, you hadn't read the letter in the box.