What does Jeremiah 40:13 mean?

Johanan privately told Gedaliah at Mizpah, 'Let me go and kill Ishmael. No one will know. Why should he assassinate you and cause all the Jews who have gathered here to scatter and the remnant of Judah to be destroyed?' Jeremiah 40:13 - Modern Text Bible

(Johanan offers to secretly eliminate Ishmael to prevent disaster, fearing the consequences if Gedaliah is killed.)