Looks like natas3 contains the same message as natas2: " There is nothing on this page "

Again I start by inspecting the element. Instead of a picture, this time we get a hint in the HTML:


This is obviously a hint that there might be something in the robots.txt. So I navigated to http://natas3.natas.labs.overthewire.org/robots.txt and found the following file:

User-agent: *
Disallow: /s3cr3t/

So I navigated to the /s3cr3t/ directory and found another users.txt file with the following content: