In recent days, the mysterious happenings in North Korea have grown slightly clearer—but potentially more serious. North Korean leader Kim Jong Un remains out of sight. He has missed two of the country’s most important political holidays, and state media has said nothing of his whereabouts since April 11. Late last week, Reuters reported that a delegation of Chinese medical professionals had flown to Pyongyang to attend to Kim.

Unless the trip is a ruse to confuse foreign observers, such movement suggests that Kim, who is believed to be about 36, is alive. But if the leadership of the proudly self-isolated country reached beyond its borders for aid, his condition likely is grave.

If Kim dies or is permanently incapacitated, North Korea faces a daunting challenge. His grandfather and father both nominated and promoted clear successors from among their many children, whereas the young dictator is unlikely to have designated an heir—and the oldest of his reputed three children is just about 10. There may be no worse political snake pit than Pyongyang, and the sudden loss of Kim as supreme leader could cause a political vacuum. The question of who could step in and take over is now paramount.

Leadership in North Korea has operated as a quasi-monarchy ever since Kim Il Sung sidetracked his brother and younger son to prepare his son Kim Jong Il to take over. The transition began early as the leader moved his son up in the party to general secretary, where the latter was able to solidify his control. On Kim Il Sung’s death, power appeared to pass smoothly. Kim Jong Il was in his 50s and had accumulated significant authority during his father’s life; any conflicts were carefully hidden from view.

When his own father died in December 2011, Kim Jong Un was in his late 20s. While observers believed Kim might end up as the frontman for a collective leadership or a power behind the throne, he proved brutally efficient in eliminating potential threats. That Kim and Kim alone would hold power became quickly apparent.

Although Kim efficiently consolidated power, there is no indication that he designated an heir. And it would be too late for a dying Kim to anoint someone. Students of pre-modern history are all too familiar with what this kind of succession crisis looks like.

The author Jieun Baek wrote in an article for the National Interest that it is essential for regime elites to rely on the sacred Mount Paektu bloodline: “While possible, it is difficult to imagine that a collective leadership will take over the state in the long run in the absence of a successor who is from the Kim family. This is because the political legitimacy of the state is derived from the mythical narrative that North Korea’s founding father Kim Il-sung is essentially a god, and his successors will continue to lead the Socialist revolution and protect the nation. North Korea without a successor from the Kim family is like worshippers going to church without a deity to worship.”

Still, as machinations before and after the youngest Kim’s appointment suggest, the ruling elite is unlikely to believe or care about the Kims’ extravagant claims. One can imagine that many of them are ready for someone else to rule. Indeed, Kim Jong Un’s murderous ruthlessness provides a good reason to move beyond royal blood.

As for the North Korean people, how much popular legitimacy does the Kim name really provide? Poverty and starvation appear to have eroded belief in the regime. Defectors aver that Kim Jong Il was less popular than Kim Il Sung, which is one reason Kim Jong Un modeled his appearance after his grandfather. To rule effectively, solid control of the system’s coercive institutions is far more important than parentage.

But who could take over? The family cupboard is bare. Kim is believed to have three children, but all are too young. And there could be no regency for them to come of age, as Kim’s wife, Ri Sol Ju, has no political role and is not blood family. Kim has at least two nephews, sons of his half-brother Kim Jong Nam—whom he had assassinated in 2017. The oldest, Kim Han Sol, is about 25. Unknown in North Korea, in hiding, and the son of an enemy, he is hardly an option.

Kim Jong Un has an older brother, Kim Jong Chol, who was passed over by their father for apparently lacking the toughness necessary to rule. Kim Jong Chol holds an unimportant political position, has no public role, and is best known for attending Eric Clapton concerts. Power will not be offered to him, nor is it likely that he could retain it if it were. An uncle, Kim Pyong Il, was sent by his half-brother into comfortable semi-exile as North Korean ambassador to several Central and Eastern European countries. Kim Pyong Il recently retired and returned to Pyongyang, where he has no public identity, no known ties with any powerful faction, and no political experience. His best qualification is being 65, which means his tenure likely would be short, allowing others’ ambitions to flourish. But he also is not going to rule.

The most likely family member, then, is Kim Jong Un’s sister, Kim Yo Jong. But she too is an unlikely candidate. Political power in North Korea has been overwhelmingly male, and society remains deeply patriarchal, even as the leaders sell themselves with maternal imagery of their “loving care” and the “mother party.” The only women with notable influence have been family members. Kim Jong Un’s aunt, Kim Kyong Hui, was trusted by her brother Kim Jong Il. His wife/consort, Kim Ok, used her position to achieve some influence, but she soon disappeared after his death.

Kim Yo Jong’s power appears to be purely derivative, bestowed by her brother, and she lacks the extensive connections and relationships that would be crucial if she took power. Kim elevated her within the party, dropped her from the politburo last year, and recently added her back as an alternate member. That is not an impressive trajectory. She is also the vice director of the Propaganda and Agitation Department, with no obvious leverage over security or military officials. She might play a role in a collective leadership and be trotted out publicly for appropriate events, but she is unlikely to emerge as No. 1, let alone the only one.

A better bet is Choe Ryong Hae, the head of the Supreme People’s Assembly and thus nominal head of state. He is the unofficial No. 2 and apparently trusted by Kim Jong Un. He is older, has broad experience, and is well tested in politics at the top. He also benefits from Kim’s institutional rebalancing, shifting authority back from the military, which was favored by his father, to the party. Reportedly, Choe was active in asserting party control over the armed forces, which may well oppose him for this reason.

There are a number of other contenders, longtime officials who have survived the political snake pit. Nor can the State Security Department and armed services be counted out. Their main disadvantage may be lack of unity among them, a conscious policy by the Kims to protect the dynasty. Kim Jong Un has regularly rotated and replaced top officials and generals. A special command oversees the loyalty of the military, given the danger it poses to political control.

The best and most realistic option probably is some form of collective leadership. It would be cautious, less provocative, and focused on ensuring regime stability and survival. There would be no denuclearization, but there was not going to be denuclearization under Kim Jong Un. A committee, as it were, would be unlikely to engage in dramatic and dangerous provocations. But it also would be likely to continue present policy, including missile and nuclear development.

A less promising alternative would be the early emergence of another strongman, whether an official frontman or back-room operator. When Kim Il Sung died in 1994, he was just a few weeks away from a summit with South Korean President Kim Young-sam. After Pyongyang criticized Seoul for not showing proper respect for the deceased dictator, relations took a sharp downturn. Another six years passed before successor Kim Jong Il met the next South Korean president, Kim Dae-jung.

Worse still would be a violent breakdown and power struggle. Different security and military units might take different sides. A Council on Foreign Relations report from 2009 warned that “a prolonged and potentially violent contest for supremacy in Pyongyang … would undoubtedly place immense stress on the rest of the country.” A full-scale civil war could result.

Refugees and fighting might cross the Yalu River into China and perhaps penetrate the Demilitarized Zone into South Korea. Nuclear, biological, and chemical weapons could emerge. The defense analyst Bruce Bennett wrote a detailed report for the Rand Corp. that warned: “There is a reasonable probability that North Korean totalitarianism will end in the foreseeable future, with the very strong likelihood that this end will be accompanied by considerable violence and upheaval.” China, South Korea, and the United States all would be interested in the outcome.

The temptation to intervene would be strong. The United States would wish to seize weapons of mass destruction, South Korea to initiate reunification, and China to preserve a pliant buffer state. Absent adequate coordination, the three countries could end up in conflict with one another. Many if not most North Koreans likely would resist. Freedom for North Koreans could come at a very high cost to any country set to intervene. Now would be a good moment for the three governments to talk about coordination should North Korea implode.

Of course, all the speculation might come to naught. Kim has disappeared from public view before, for more than a month in 2014, before reappearing. He apparently had surgery on his foot. The regime might currently delight in misleading and embarrassing the international media.

But despite South Korean government reassurances, it seems more likely that Kim is seriously ill. He missed the celebration of his grandfather's birthday on April 15, the most sacred day on the North Korean calendar, and then the April 25 anniversary for the founding of the Korean People's Revolutionary Army. Nor has the regime taken the easy step of demonstrating his health and control. Something is not right. U.S.-North Korea talks weren't likely to go anywhere anytime soon even before his apparent illness. They almost certainly won't be going anywhere now. And we might come to look at this time as the calm before North Korea's political storm hits.