Some very clever aliens have captured you. As a test of your intelligence, they have poisoned you and placed the antidote in one of two vials, with the second vial containing more of the same poison. They won't tell you which is which. Instead, Vial A has a label that reads, “The label on the other vial is true, and this is the antidote.” Vial B has a label that reads, “The label on the other vial is false, but it contains the antidote.” Which vial should you drink?
You should drink both vials. The answer cannot be determined from the clues, and if you think about it too long the poison will kill you. Even though you are sure to drink more poison, you are also sure to drink the antidote..