  TOI-1266c is a recently discovered super-Venus in the radius valley orbiting
an early M dwarf. However, its notional bulk density ($\sim$2.2 g cm$^{-3}$) is
consistent with a large volatile fraction, suggesting that it might have
volatile reservoirs that have survived billions of years at more than twice the
Earth's insolation. On the other hand, the upper mass limit paints a picture of
a cool super Mercury dominated by >50\% iron core ($\sim$9.2 g cm$^{-3}$) that
has tiptoed up to the collisional stripping limit and into the radius gap.
Here, we examine several hypothetical states for TOI-1266c using a combination
of new and updated open-source atmospheric escape, radiative-convective, and
photochemical models. We find that water-rich atmospheres with trace amounts of
H$_{2}$ and CO$_{2}$ are potentially detectable (SNR $>\sim 5$) in less than 20
hours of JWST observing time. We also find that water vapor spectral features
are not substantially impacted by the presence of high-altitude water or ice
clouds due the presence of a significant amount of water above the cloud-deck,
although further work with self-consistent cloud models is needed. Regardless
of its mass, however, TOI-1266c represents a unique proving ground for several
hypotheses related to the evolution of sub-Neptunes and Venus-like worlds,
particularly those near the radius valley.
