The white box says "There is nothing on this page" (again).
Here is the page’s code (without the header):
<body> <h1>natas3</h1> <div id="content"> There is nothing on this page <!−− No more information leaks!! Not even Google will find it this time... −−> </div> </body></html>
All right, it said Google couldn’t find it, which probably means something about robots.txt. How about we take a look at it? We navigate to http://natas3.natas.labs.overthewire.org/robots.txt and see this:
User−agent: ∗ Disallow: /s3cr3t/
It looks like the folder named s3cr3t is disallowed. If we navigate to http://natas3.natas.labs.overthewire.org/s3cr3t/ we see an index of /s3cr3t, with a file named users.txt.