舟山岛
In late 398, the magician Sun Tai (孫泰), a friend of Sima Yuanxian's, who had gathered great following due to his magic, was exposed as planning a plot to take over the central government, and Sima Daozi ordered Sima Yuanxian to trap Sun Tai and execute him. Sun Tai's nephew Sun En fled to Zhoushan Island and planned revenge.