This undated picture, released from North Korea's official Korean Central News Agency on June 4, 2010, shows North Korean leader Kim Jong Il inspecting the machine plant managed by O Mun Hyon in North Pyangan province.
As a foreign correspondent living in China, there's little that is harder to cover than a visit by the reclusive North Korean leader Kim Jong Il. For a start, sightings of the man himself are extraordinarily rare. And this time -- Kim reportedly was in China on Thursday for his second visit this year -- it's even more complicated.
South Korean foreign ministry sources say they believe he may be accompanied by his son and putative heir, Kim Jong Un, but since nobody is entirely sure what Kim Jr. looks like, confirming his presence presents an even greater difficulty. It's often like a black hole of information, where circumstantial clues add up to the fact that he must be here, rather than anyone actually having seen him.
Kim is believed to fear air travel, and travel only by train. But his normal route, through the North Korean city of Sinuiju, over the border to the Chinese city of Dandong, has been blocked this time by widespread flooding.
So it's believed he entered China near the city of Jian. Reports say he made a 20-minute visit to Yuwen Middle School in Jilin, some 155 miles from the North Korea border. This is the alma mater of his father, revolutionary leader and eternal president of the Democratic People's Republic of Korea Kim Il Sung.
The Associated Press quotes a PE teacher at the school who says, "He definitely came over. But I'm not sure if his son was with him or what time he came."
That doesn't sound like a sighting.
Our efforts to confirm his presence at the school were unsuccessful. The school's switchboard operator was, by the time we called, practiced at refusing to answer questions. Staff at two nearby restaurants could only confirm police had blocked the road to the school between 10:30 and 11 a.m.
Someone, however, had posted an internal school notice online, dating from yesterday, which said, "Kim Jong Il will pay a visit to our school, Jilin Yuwen Middle School tomorrow morning. We have been informed to finish school early today and tomorrow morning will be holiday."
We know there is heavy security near the five-star Crystal Hotel in Jilin this evening. But definitive sightings? You should be so lucky.
It's also reported that the North Korean leader visited Beishan Park in Jilin. This is significant because it marks the burial site of anti-Japanese independence fighters. This weekend marks the 100th anniversary of Japan's annexation of Korea, so Kim could be visiting these sites to burnish his dynasty's revolutionary and anti-Japanese credentials, ahead of a move to transfer power to his son, Kim Jong Un, at the Worker's Party Congress, which is due to be held in early September.
Japan's Kyodo News agency reports that China's vice premier and future leader, Xi Jinping "seemed to be accompanying" Kim on his travels, which could bolster the theory that this is a courtesy visit to introduce his son to Chinese officials. But again, that "seems to" indicates a remarkable lack of clarity.
It is clear that Kim's absence at the exact moment when former President Jimmy Carter is in Pyongyang is a diplomatic snub of the highest order. Carter is trying to win the release of American prisoner Aijalon Mahli Gomes, who was sentenced to eight years of hard labor for trespassing onto North Korean territory.
This is being touted as a "private humanitarian mission," but one report indicates Carter's visit has been prepared with extensive participation from officials in the State Department and National Security Council. So for Carter to be kept waiting, kicking his heels in Pyongyang while Kim tours northeastern China, is likely to intensify the debate about the value of hostage diplomacy.
But beyond that, practically nothing is known. North Korea's grim economic situation has been worsened recently by the recent flooding, so some analysts believe that Kim is visiting China in a desperate bid for more economic aid. Others have posited he may be asking for money to put on a good show at the upcoming congress. Some say he's seeking new weaponry. There's speculation that Kim's health could have worsened -- he suffered a stroke in 2008 -- leading him to seek urgent treatment in China. And some have wondered if the visit is linked to Chinese efforts to revive North Korean nuclear disarmament talks.
But the truth is nobody knows. As one South Korean cynic told me today, "Being a North Korea expert is the easiest job in the world. Nobody can ever prove you wrong."