Desperate for military aid, Soon-shin puts his sword to Yi Il's throat, but it is useless. In Nokdune Island, the fear of imminent Jurchen attack is getting to the soldiers' heads. Meanwhile, Toyotomi Hideyoshi of Japan sends his envoy to Chosun demanding that Sonjo come to Japan before him. Soon-shin is called to attend the officers meeting held in Kyung-heung. But he can't leave his fort for a second with the imminent Jurchen attack. Yim Kyung-bun convinces him to go telling him that this could be his last chance to acquire military aid. The Jurchen nomads attack while Soon-shin is away.
—https://www.yidio.com/show/the-immortal-yi-soon-shin