Over the past several years, the observed orbital geometry of extreme trans-Neptunian objects has provided tantalizing evidence predicting the existence of an as-yet undiscovered super-Earth, commonly referred to as "Planet Nine", in our home planetary system. The presence of a long-period super-Earth in the solar system would fundamentally alter our current paradigm of how the solar system fits into the broader distribution of planetary systems. The evidence for Planet Nine, however, relies heavily upon the observed alignment of only a handful of objects. A thorough search for additional dim outer solar system objects – including, perhaps, Planet Nine itself – is necessary to understand the robustness of this hypothesis. I will provide a brief overview of the Planet Nine theory and an innovative path forward in the associated observational search: a direct optical/infrared search leveraging data from the Transiting Exoplanet Survey Satellite (TESS). I will present results from a newly developed TESS pipeline that is capable of extracting signals from dim solar system objects objects down to V~22 by aligning and co-adding TESS full-frame images. Together with the extensive sky coverage of the TESS survey, this search method will place stringent constraints upon the existence of undiscovered trans-Neptunian objects, with great potential to either discover Planet Nine or almost entirely rule out its existence.