Chinese micro-bloggers and overseas websites are agog with all kinds of speculation as to why Xi Jinping, the current vice-president and president-in-waiting, has gone unseen for more than a week.
During that span, Xi cancelled meetings with visiting foreign dignitaries including US Secretary of State Hillary Clinton and Singapore prime minister Lee Hsien Loong.
On Monday, it was the Danish prime minister's turn. A scheduled photo session with visiting PM Helle Thorning-Schmidt, which the media were asked to cover, was taken off the programme.
Thorning-Schmidt was also due to meet Vice-Premier Wang Qishan on Monday and Premier Wen Jiabao on Tuesday.
The foreign ministry claimed Xi's meeting with Thorning-Schmidt was never intended to take place.
Reactions from Chinese social media
Although mainstream media in China have steered clear of speculating on the whereabouts of Vice President Xi Jinping, the country’s social media has been increasingly vocal.
The internet traffic has been heavily censored. For example, a search for "vice president" or "Xi Jinping" returns with no results - only a warning that according to the relevant regulations and policies the results cannot be displayed.
There are few facts about Xi's mysterious absence, but plenty of rumours.
Here are three typical comments from Chinese social media site Sina Weibo:
"For all we know, he could be just taking a holiday somewhere before the big day. We'd understand if they could just tell us, but here we are, all conspiring."
"Typical in a year of Chinese top political circle mysteries. I'm sure we'll find it less exciting if our glorious party just tell us what is going on honestly."
"A back injury from swimming? Football? They try so hard to hide this. At least this sounds like he’s only human. But of course, being human is not acceptable for Chinese party leadership."
"As I said last week, China's state councillors will meet the Danish prime minister," foreign ministry spokesman Hong Lei said.
When asked about the rumours of an injury, Hong said, "We have told everybody everything," and refused to elaborate.
Rumours about Xi were churned further by Russian President Vladimir Putin's cryptic remark over the weekend that the start of the Asia Pacific Economic Co-operation forum leaders' meeting in Vladivostok had been delayed because President Hu needed to attend to an important but unspecified domestic issue.
Xi's whereabouts during this sudden absence from the spotlight may never be known. One thing, however, is certain: China may now be a linchpin of the global economy and a force in international diplomacy, but the lives of its leaders remain an utter mystery to its 1.3 billion people.
"There is a longstanding practice of not reporting on illnesses or troubles within the elites," said Scott Kennedy, director of Indiana University's Research Centre for Chinese Politics and Business in Beijing. "The sense is that giving out such information would only fuel further speculation."
Wang Xiangwei, editor-in-chief of Hong Kong's South China Morning Post and a longtime state media insider, wrote on Monday in his newspaper that Chinese leaders' meetings are planned well in advance and cancelations are extremely rare.
"Barring Xi himself offering a very unlikely explanation today about his cancelled meetings last week, the outside world may never know the exact reason, and the rumours are unlikely to fade away," Wang wrote.
Though absent in person, Xi did appear on Monday on the front page of the party academy's official newspaper Study Times alongside a transcript of the speech he delivered nine days earlier.
In the text, he enjoins newly enrolled cadres to use their time on the leafy campus in the northern Beijing suburbs to think critically about major national issues and not spend it "expanding personal contacts and inviting guests to dinner".
This year, China has seen an unusual amount of political intrigue, with the spectacular downfall of Politburo member Bo exposing divisions within the leadership and prompting rumours of nefarious activity ranging from the wiretapping of top leaders to an attempted coup.
The sudden transfer of a key secretary to President Hu Jintao earlier this month also spawned conjecture about a Ferrari crash involving the aide's son and an ensuing attempted cover-up.
The tension and uncertainty are heightened by the timing ahead of a generational shift to a new leadership that is to be headed by Xi. Still, in keeping with the China government's proclivity for secrecy, the logistics of the transition remain unknown.
Xi is expected to first assume Hu's mantle as Communist leader at a party congress held once every five years. Yet, the dates for the meeting, expected in the second half of October, have yet to be announced, prompting talks that at least some of the seats on the nine-member Standing Committee remain up for grabs.
Most online speculation about the portly 59-year-old Xi has centred on a back problem, possibly incurred when he took a dip last week in the swimming pool inside the Zhongnanhai leadership compound. Another rumour has his back being hurt in a soccer game. It was not clear what the sources of the information were.