There is a village somewhere in England that has not been inhabited for over twenty years. It has long since been forgotten off of most maps, and only has one road in and out of it. If you manage to find it, it will seem a peaceable enough place, the derelict buildings being overgrown and nature taking back the land for herself.
However, somewhere within the village is a vending machine which still has power. It will still have its original look and sell ordinary brands of drink (though with 20 year old packaging). The one at the bottom will be marked "E." Pay only in 10p pieces to buy this drink.
Before drinking the mysterious beverage, peer inside the can to check its color. Do not try to pour some out. It will refuse to leave the can despite any vigorous shaking you may attempt. If it is green in color, drink heartily, as it will give you an unnaturally long lifespan and good luck in everything you do.
If it is red, however, drinking it will spread a horrific pestilence over you, claiming one of your senses every ten years after the date that you first imbibed.