After successfully exposing Victor's crimes and building a deep bond with Sophia, Allen decides to continue his detective work and bring justice to more victims. On the occasion of the official establishment of Allen's detective agency, he receives a new case.

The case involved a young woman named Lisa. On a sunny morning, she was horrified to find her husband, Martin, dead in his study at home. The cause of Martin's death is puzzling, and after a preliminary investigation, police found that his death was linked to a mysterious poison needle. The needle pierced Martin's neck, rendering him defenseless.

The police launched an in-depth investigation into the scene of the crime, but did not find any clear evidence. Since there were only two people in the family at the time of the crime, Lisa and Martin were the only two people in the house, and the police suspected that Lisa might be Martin's killer. However, Lisa vehemently denied that she had anything to do with her husband's death, and she wept bitterly to assure the police that she had no motive for the crime.

During the interrogation, the police found that Lisa and Martin's marriage was not happy, but this was not enough to prove that Lisa was the murderer. With nothing to be found, the police decided to enlist the famous detective Allen to assist in the investigation. Allen has successfully solved a number of difficult cases before and won the trust of the police.

Lisa was slightly relieved to learn that the police had invited Allen to investigate the case. She knows Allen's talent and sense of justice, and believes that he will be able to find out the truth and return his innocence. And after Allen accepted the investigation mission, he immediately threw himself into the case, and he vowed to find out the truth and give justice to the dead and the living.

Alan first came to the scene of the crime, Martin's home. Accompanied by the police, he entered the scene of the crime, Martin's study. Martin's body has been removed, but traces of that time still remain at the scene.

After careful investigation, Alan found Martin's body clutching a note in both hands when it was found. There was a strange symbol written on the note, which seemed to be some kind of password or code. Allen thinks that this symbol may hint at the truth behind the case.

In addition, Alan also noticed that there were some papers scattered on Martin's desk. One of the documents piqued Allen's interest because it showed Martin working on a rare and highly poisonous plant called "wisteria". This plant grows in remote tropical areas and is extremely poisonous, and is said to kill people in a short period of time. Allen suspects that these clues are closely related to Martin's death.

To further investigate, Alan asked Lisa about the document. Lisa says she doesn't know anything about Martin's research, but admits that Martin does have a passion for rare plants. Allen felt compelled to dig deeper into Martin's study to see if it was related to his death.

In the course of his investigation, Alan also discovers that there is a crack in Martin's marriage with Lisa. According to Lisa's neighbors and friends, Lisa has been suspicious of Martin having an affair, which has led to tensions between the two.

Alan decided to dig deeper into the plot. During a conversation with Lisa, Alan discovers that Lisa is indeed suspicious of Martin's whereabouts. She said that Martin has often returned late late, and his whereabouts are mysterious. Whenever she asked why, Martin was always at a loss for words. Lisa suspects that Martin may be entangled with another woman behind her back.

However, during Allen's investigation, he found that the reason for Martin's late return seemed to be related to his botanical research. In Martin's notebook, Alan found records showing that Martin often went to a deserted laboratory at night to conduct experiments, and this laboratory was related to the study of wisteria.

Although Allen did not find conclusive evidence that Martin was having an affair, he believes that Martin may have concealed his research whereabouts because he was worried that Lisa had misunderstood. This, on the contrary, deepened Lisa's misunderstanding and distrust of Martin.

To clear up this misunderstanding, Allen decides to investigate Martin's lab to see if he can find further clues. He hopes to find evidence that Martin is not having an affair, and to uncover the true purpose of Martin's research on wisteria. All of this will be the key to the truth of the case, leading Alan to the heart of the truth.

During the investigation, Alan discovers a strange phenomenon: Martin did have contact with a mysterious woman during his lifetime, but their relationship does not seem to be an affair, but revolves around a common goal. Alan decides to dig deeper into the identity of the mysterious woman in order to unravel the mystery of Martin's death.

During the investigation, Alan discovers a strange phenomenon: Martin did have contact with a mysterious woman during his lifetime, but their relationship does not appear to be an affair. Judging from their correspondence, the conversation between the two men revolved around a common goal and was closely related to Martin's botanical research. Alan decides to dig deeper into the identity of the mysterious woman in order to unravel the mystery of Martin's death.

Alan first started with Martin's correspondence records to find out where they had met. After some investigation, Alan finds a café and finds a picture of a mysterious woman. She is beautiful, seemingly quiet and elegant, but she reveals a mysterious atmosphere. Alan noticed that the woman's name was Susan, and she was a botanist in the same field of study as Martin.

Alan found Susan's contact details and got in touch with her. During the conversation, Alan learns that Susan and Martin have indeed collaborated, but their goal is to study the mysterious properties of the wisteria and explore its potential value in the field of medicine. Susan said she and Martin have always maintained a purely academic partnership and have never been emotionally entangled.

Allen's discovery is a relief to Lisa, as it means that Martin hasn't betrayed her. However, the truth of Martin's death is still mysterious, and Alan must find out the truth as soon as possible to get justice for Martin.

As the investigation deepens, Allen discovers that Susan and Martin had once caught the attention of a criminal organization because of their research on wisteria. This criminal organization intends to use the poison of wisteria to make weapons and make huge profits. Allen suspects that Martin's death may be related to this criminal organization, and he decides to investigate more deeply and reveal the truth.

Allen, who knew the truth, reported the situation to the police. With Allen's help, the police eventually determined that Martin's death was not a homicide, but a tragic accident. When Lisa learns the truth, she is deeply saddened. Although her marriage to Martin was not perfect, she always loved this man who had fought desperately for love.

After this incident, Alan realizes that love and life can be so complicated at times. He and Sophia went through this investigation together, and the two became more affectionate towards each other. Alan promises that no matter how difficult the future may be, he will be with Sophia.

The resolution of this case once again proves Allen's detective talent. His firm's reputation is far and wide, and more and more people are coming to him for help. And Alan and Sophia continue to walk side by side on the road of justice, seeking the truth for countless victims and giving them a fair world.