Wang Lijun's whereabouts between Monday 2/6/2012 and Wednesday 2/8/2012 might never be confirmed by either Chinese or American government. We may never know what happened inside the US Chengdu General Consulate. Having that said, below is one most plausible plot:
In the months leading to the final show down, Wang should have already sensed Bo's malice. Because of Bo's absolute power in Chongqing, as well as his political clot in the nation, Wang has no chance at all to fight back. Judging from Bo's track record, it was logical for Wang to believe Bo would harm him and very possibly his families and friends. Therefore, it amounted to a duty and obligation for Wang to strike back.
The US consulate is picked perhaps because it is the only place in the southeastern China where Wang can have a direct and uninterrupted communication with central government in Beijing. Wang was under tight monitoring long before he had been stripped off Police Chief duty. He was not allowed to travel. If he try to flee on foot, he might be immediately arrested, or quietly killed as a fugitive.
Wang jumped on an opportunity when he was arranged to inspect a local university as a stage-show to tell the public everything had been normal. He fled in disguise and drove an unmarked car to the capital city Chengdu of neighboring Sichuan Province, where he scheduled a meeting with the US consulate. The Consulate arranged him to sneak in the US General Consulate in Chengdu. However, Wang was identified by a security agent working for the central government.
What happened in the next 24 hours was not clear. Wang might left some important evidence to prove Bo's involvement in crimes. Wang might discusses refuge or asylum status issue with US officials. Wang might spoke to some senior officials in Beijing. Wang might had a talk with his boos Bo.
In the end, outside the consulate there was an armed stand-off between paramilitary troops equipped with heavy equipment from Chongqing and local police who are reinforced by security forces belonged to central government. Bo tried to take Wang back to Chongqing by force, but was pushed back by Beijing.
The US General Consular was not in the consulate at the time on Tuesday night. He went out for unknown reason but could not come back because of road blocks and a man-made traffic jam. Wang received a call from a commander outside the consulate. Wang was told if he did not walk out, then police would break in using the excuse that there might be a bomb inside the building. Wang contacted the General Consular again, and was told he did not know when could he get back to the consulate. Wang decided to walk out. Spokesperson of the US State Department said Wang walked out in his own volition. She also stated there was no threat to the Chengdu Consulate, and US did not request increased security to the consulate.
While Wang walked out, he shouted to police surrounded the building that he had collected evidence of crimes committed by Bo Xilai. Bo was taken by the security forced loyal to the central government, and flown to Beijing within hours.
Now that it had become an international incident. The central government will have legitimate excuse as well as a procedural obligation to launch an investigation against Wang's charges against Bo. It is revealed that a high level delegate had stationed the Jinniu (Golden Bull) Hotel in Chengdu since the incident, and that there was no sign they were leaving anytime soon.