Louis is a bit of a petulant brat, what if he falls out with Treville and dismisses him. The musketeers are not impressed and each one does his best to encourage his new replacement to quit.

They can't be outright insubordinate, so I leave it to you, anon, what they do. Eventually they succeed. Louis meanwhile has missed Treville and invites him to return to his position as Captain of the musketeers.