A serial killer gave each of five victims two pills and a glass of water. He told each to take one pill, warning that one was poisonous. The killer took the other. Every victim died. How did the killer always survive?

Why this works

At first glance, this riddle seems to weave a tale of horror that leaves you pondering the sinister mind of a killer, but the true twist lies in the cunning misdirection regarding the pills and the glass of water. The killer's assurance that one of the pills was poisonous is a clever decoy, leading the victims to focus on what they were consuming rather than the lethal water itself. By taking the antidote of the other pill while the victims unwittingly drank the poisoned water, the killer effectively manipulated their choices and sealed their fates without ever putting himself in danger. This riddle is particularly satisfying because it plays with the classic themes of trust and betrayal. Water, often considered a source of life, here becomes the instrument of death, creating a chilling contrast that heightens the drama. The riddle also uncovers an intriguing layer of human psychology—how easily we can be misled when we fixate on the obvious, neglecting the subtler threats lurking in the background. As a fun tidbit, this riddle echoes the themes found in classic detective stories and psychological thrillers, where appearances can be deceiving and the true danger often lies in the most unsuspecting places. It reminds us that in both riddles and real life, the most straightforward solutions are sometimes the ones we overlook entirely!