Why Is There An Armored Train In Beijing? Is It Kim Jong Un's?

The Chinese capital is gripped by mystery that includes an armored train, amateur detectives and flurry of Internet searches for "fatty the third."
On Monday afternoon, an unusual train chugged into Beijing Station under tight security. Passengers disembarked and boarded limos. After nightfall, a motorcade drove to a state guesthouse where foreign dignitaries often stay.
But after more than 24 hours of speculation about a possible visit by a senior North Korean leader, perhaps even Kim Jong Un, it is not yet clear who was actually on the train, or why. Was it Kim? His sister? Somebody else?
The White House can't confirm. The South Koreans are quiet. And a spokesperson for the Chinese Foreign Ministry said at a daily press briefing on Tuesday that she has "no information" about the green and yellow train or the very, very long motorcade.
Chinese netizens looking for answers hit a wall: On Tuesday, three of the top 10 blocked terms on Weibo, a microblogging site, were "Kim Jong Un," "North Korea" and "Fatty the third," a popular Chinese nickname for Kim, according to freeweibo.com, a website that tracks censorship.
The fact that nobody is talking is particularly striking given the timing; the train arrived in the run-up to Kim's summit with South Korean President Moon Jae-in in late April and his possible meeting with President Donald Trump in May.