Riddle of the Week

Riddle of the Week: A Game of Poison

Difficulty level: Hard

Michael Stillwell
 
By Jay Bennett

Welcome back, welcome back. For this week's riddle we take a look at two people trying to outwit each other. A scheme is concocted, realized, and then countered. One man ends up lying dead on the floor.

PROBLEM

In a faraway kingdom, there is a mysterious herb. The poisons brewed with this herb break down in the body for a number of minutes, and then they cause sudden death. But there is a catch: If you drink a stronger poison brewed with the same herb while the first poison is still breaking down in your system, then it will neutralize the weaker poison and act as an antidote, saving your life.

The king in this land wants to posses the strongest poison in the realm, so that he may save his own life should anyone try to poison him. He summons his pharmacist and his treasurer.

"Each of you will brew me the strongest poison you can," he commands. "Next week, you will each drink the others' poison, and then your own. Whoever brews the stronger poison will live, and the other will die."

The two immediately set to work, but it doesn't take the treasurer long to realize that he cannot possibly brew a stronger poison than the pharmacist. It's just not his area of expertise. And so he devises a plan to survive.

The pharmacist, meanwhile, is almost done with his poison, a strong brew that is about as potent as possible. But the day before the potion-drinking showdown, he comes to an important realization: The treasurer must know the pharmacist's brew will be stronger, and if he wants to live, he must be thinking up an alternative plan. After some thought, the pharmacist realizes what the treasurer must be planning, and he devises a counter ruse.

The next day, the pharmacist and the treasurer appear before the king. They each drink the others' potion, and then their own. The treasurer dies, the pharmacist lives, and the king doesn't get what he wants.

What happened?

HINT

It will help to reread the first paragraph of the problem. Then, the key to solving the whole riddle is first figuring out this question: What was the treasurer's initial plan?