In an ancient empire called Rhuidean, it was known that if you drank poison, the only way to save yourself is to drink a stronger poison, which neutralizes the weaker poison. The queen that ruled the land wanted to make sure that she possessed the strongest poison possible, in order to ensure her survival in any situation. So the queen called the best alchemist and the best wizard and she gave each a week to make the strongest poison. Then, each would drink the other one's poison, then his own, and the one that survived would be the one that had the stronger poison.
The alchemist went straight to work, but the wizard knew he had no chance, for the alchemist was much more experienced in this field, so instead, he made up a plan to survive and make sure the alchemist dies. On the last day the alchemist suddenly realized that the wizard would know he had no chance, so he must have a plan. After a little thought, the alchemist realized what the wizard's plan must be, and he concocted a counter plan, to make sure he survives and the wizard dies. When the time came, the queen summoned both of them. They drank the poisons as planned, and the wizard died, the alchemist survived, and the queen didn't get what she wanted.
What happened?