It has been widely suspected that the Kim Jong-un’s next target would be his nephew after he had his half brother murdered:
Chinese police arrested several North Koreans dispatched to Beijing on suspicion of plotting to murder Kim Jong Un’s 22-year-old nephew, South Korea’s JoongAng Ilbo newspaper reported.
Two of seven North Korean agents were arrested over the alleged plot to kill Kim Han Sol, whose father Kim Jong Nam was assassinated in Malaysia earlier this year, the newspaper said, citing an unidentified person familiar with North Korean issues.
Some agents are being interrogated in special facilities on the outskirts of Beijing, the paper said, without elaborating on whether the other five were arrested. China’s foreign ministry didn’t immediately respond to a faxed request for comment. [Bloomberg]
You can read more at the link, but if this plot was broken up in China it leads me to believe that Kim Han-sol must be in hiding in China under Chinese protection.