On the weekend again, the famous chemist Professor Kai invited two old friends to his house to play bridge. One was his assistant, Associate Professor Veronica, and the doctor Parker and Physics J. Henry. They played bridge and tasted the snacks prepared by the hostess.

Associate Professor Veronica left her seat and went to the living room to pour a glass of brandy for everyone.

"Veronica, hurry up! The cards are dealt, let my wife get the wine." Professor Kai couldn't wait any longer. The hostess was afraid that everyone would get the wrong wine glasses while playing cards, so she put a colored napkin under everyone's wine glass. Everyone gets their own wine glass according to their favorite color.

The hostess asked the associate professor which cup he wanted, and the associate professor said he wanted the one on the sky blue napkin. The associate professor took the glass and drank it in one gulp. Suddenly he fell to the ground with his mouth half-opened and his eyes widened. The forensic doctor found potassium cyanide in the stomach of the associate professor's body, and the poison was placed in brandy.

The next day, those who played bridge at the professor's house were summoned to the police station. The police chief told everyone about the associate professor's death verdict. The police officers on the side observed carefully, trying to find people with abnormal reactions. However, none of these people looked uneasy at all.

The Sheriff couldn't see anything suspicious, so he had to let them go back.

After they left, the sergeant asked the police officer if he had noticed anything unusual. The police officer shook his head and the sergeant said, "Let's visit alone."

Sure enough, from then on, Physicist Henry knew that Professor Kai and Associate Professor Veronica were developing a new type of material that was stronger than any alloy steel, easy to shape, and extremely fire-resistant. It was an ideal aviation material. Raw materials for manufacturing. This research has attracted the attention of many large foreign companies. The sudden murder of the associate professor is most likely related to the research results.

In the next few days, several more witnesses came to the police chief. From the analysis of the situations these people talked about, it seemed that everyone might be the murderer because they all had resentment towards the deceased. . The police chief also learned that the relationship between the associate professor and the professor was not good because the associate professor wanted to keep the research results to himself.

The Sheriff also learned that that day, the associate professor told the hostess that his wine glasses were on sky blue paper. The hostess took two glasses from the table, one to Professor Kai and the other to him. To the associate professor. The forensic doctor saw that the sky blue wine glass had not been moved at all, so the hostess was also suspicious. The next day, the police chief called the hostess, and the police chief brought a piece of sky blue paper and a piece of pink paper. He asked the hostess to sign on the sky-blue paper to archive the confession materials. After the hostess left, the police officer discovered that she had signed her name on pink paper. "What's going on?" he asked. "You'll find out tomorrow," the sergeant said mysteriously.

The next day, everyone related to the case was invited by the police chief to the home of Professor Kai, who was going to do a simulation experiment related to the case. Everyone took their seats according to where they were playing cards that day, and the deceased associate professor was replaced by a police officer. The hostess asked the assistant, who was playing the role of associate professor, the color of the napkin placed under the wine glass. The assistant said it was sky blue. As the hostess handed over the glass, the sergeant shouted to stop.

At this time, everyone discovered that the napkin under the wine glass handed to the assistant was pink, and the wine glass on the pink napkin should belong to Professor Kai. The glass on the sky blue napkin was still on the table. .

The police sergeant said slowly: "Now you understand, the murderer is the associate professor himself!" What happened? As a result, the associate professor poisoned the wine with the intention of poisoning the professor to death. Unexpectedly, the associate professor poisoned the wine. The hostess is color blind and took the wrong wine glass.