wp_editor() renders outside wrapping div

If have a plugin with a text box. I wish to replace the text box with an editor.

My source code is

I expect that the editor will render within the div however here is the source code from the page.

The editor is right at the top of the entry-content div and my div is at the bottom of this sample.

What is the trick to getting the editor inside a div in a specific position on the page, rather than at the top?