It should be noted that the author, Richard P. Stanley, is a well-known M.I.T. mathematician.

Although providing technical details to accompany a light story like this might ruin the fun (like explaining the punchline of a joke), let me explain a few things for those who may not know. Nineteenth-century mathematician Bernhard Riemann introduced a function ζ(z) defined for every complex number except z=1. Since the definition of the function involves all of the prime numbers, a thorough understanding of the function could reveal something of their mysterious pattern. However, much about this "Riemann zeta function" remains mysterious itself. Most famously, we do not know the location of all of the roots of the function (i.e., all of the input values for which the output values are zero). The Riemann Hypothesis is the famous open conjecture that these all occur either at negative real integers or along the "critical line" Re(z)=1/2. The graph of ζ(z) would be difficult to imagine because the input and output values are both complex numbers. So (in terms of real numbers) the graph would exist in a four-dimensional space. In this story, however, the character stands on the graph of |ζ(z)|, which is a real number and hence the graph would be a surface over the complex plane. The zeroes would occur at the points where the graph's height reaches its minimum value of zero, and the singularity at z=1 becomes an infinitely tall pole that Eubanks climbs.

This story reminds me of the scenes in Miriam Webster's After Math (1997) in which a mathematician visits a dreamlike landscape in order to prove theorems.

Spoiler alert: The next paragraph contains a minor spoiler.

Publication details: Stanley, R.P. Professor Eubanks in Zetaland. The Mathematical Intelligencer 10, 21–23 (1988). https://doi.org/10.1007/BF03026637