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The one-day murder trial of Gu Kailai, the wife of ousted Chinese politician Bo Xilai, concluded with prosecutors telling the court that she slipped poison into a glass of water to kill British businessman Neil Heywood after he got drunk.

Gu killed Heywood, they argued, because he threatened the security of her Harvard University son.

The closed door trial and the speculation around it has all the intrigue of a spy movie thriller. It is taking place while the leadership of the Chinese regime prepares to undergo a once-a-decade change of power. The country's leadership appears intent on distancing itself from her, but trying to avoid delving too deeply into her financial shenanigans for fear of putting a spotlight on the lifestyle of China's rulers.

Gu and a family aide Zhang Xiaojun stood behind barred podiums in front of the Intermediate People's Court in the eastern Chinese city of Hefei as prosecutors detailed how they believed Gu murdered Heywood, who once had close financial ties with the Bo family.

Heywood was found dead in his hotel room in the southwestern Chinese city of Chongqing in November of last year and Gu was fingered as the main suspect and Zhang as an accessory to murder.

Click here a brief history of the Bo Xilai saga.

According to China's Xinhua News Agency, the prosecutors claimed that Gu and her son Bo Guagua "had conflicts with Neil Heywood over economic interests. Worrying about Neil Heywood's threat to her son's personal security, (Gu) Kailai decided to murder Heywood. "

Gu reportedly asked her aide Zhang, then an employee of the local Communist Party committee, to invite and escort Heywood to Chongqing for a meeting.

On Nov. 13, 2011, Gu met with Heywood for a drink in his hotel room and they drank until Heywood became drunk.

Upon vomiting, he asked Gu for water. It was then Gu reportedly poured the poison "she had prepared" into Heywood's mouth. It was been reported earlier this year by the Daily Telegraph that the poison in question was cyanide.

The defense team argued that Gu had "weak self control" and was in a fragile state of mind.

"The trial finished this afternoon and the court adjourned," court official Tang Yigan told reporters in press conference.

"The court will, during the adjournment, seriously and thoroughly consider the evidence, take into consideration the arguments of both sides, and according to facts and the law … the trial committee will announce the verdict after discussion. The date of the verdict will be announced."

The timing and location of the trial is also of note. Hefei, though the provincial capital of Anhui, is far removed from Beijing, Chongqing where Bo once governed or the port city of Dalian where Bo was mayor in the 1990s.

While the focus of the media is trained at the closed doors of the Hefei courthouse, the Communist Party leadership is holding their summer conclave where they are reportedly deciding on the future direction of China.

Gu Kailai's trial is considered the highest profile court case in China in over the last three decades and comes at a particularly sensitive time for China as the Chinese leadership prepares to undergo a once-a-decade change of power.

It has been reported that Heywood was suspected to have helped Gu funnel their family wealth outside of China, but the government has chosen not to charge Gu with financial crimes. This could be a sign the government may have been wary of setting a precedent for exposing the similar practices by the relatives of other members in Chinese leadership.

Gu is also considered the most vulnerable person in the case because she is the only one whose conviction would not directly shame the party.

The murder charge, with the flourish it was presented on Thursday, is likely a done deal. China has a 98 percent conviction rate and the criminal code under which Gu was tried carries a death penalty.

There is, however, a chance she could receive leniency. It is noteworthy that state-run media and the prosecution claim that her actions were taken to protect her son, Bo Guagua. The younger Bo recently received his master's degree from Harvard University, and is believed to still be living in the U.S. On the eve of his mother's trial, Bo Guagua issued a statement to CNN saying, "I have faith the facts will speak for themselves." He told CNN that he submitted a witness statement to his mother's defense team.

Some in China are comparing Gu's trial to that of another party leader's wife, Mao Zedong's widow Jiang Qing. In 1980 Jiang and three confidants, known as the Gang of Four, were tried and convicted for masterminding political upheaval at the time.

The scandal involving the Bo family is the biggest scandal to rock China in a generation. Bo Xilai had for years been a powerful, rising member of the Communist Party in charge of Chongqing. He fell from grace in spectacular fashion this past spring.

Bo's own police chief, Wang Lijun, sought refuge at the U.S. consulate in Chengdu, reportedly presenting U.S. officials with incriminating evidence of corruption against both Bo and Gu. He feared for his life because of his direct connection to them both. He is believed to be held by authorities in Beijing, but has not been seen or heard from for months.

Though the Chinese government wants this episode over, more details are about to emerge. In a separate trial, four Chongqing police officers are expected to be charged with conspiracy Friday in helping to cover Gu Kailai's tracks.

ABC News' Asia Correspondent Gloria Riviera contributed to this report