  The radio source FIRST J102347.6+003841 was presented as the first
radio-selected cataclysmic. In the discovery paper, Bond et al. (2002) show a
spectrum consistent with a magnetic AM Her-type system and a light curve with
rapid, irregular flickering. In contrast, Woudt, Warner, and Pretorius (2004)
found a smoothly-varying light curve with a period near 4.75 h and one minimum
per orbit, indicating a dramatic change. We present time-resolved spectra
showing a superficially normal, mid-G type photosphere, with no detectable
emission lines. The absorption-line radial velocity varies sinusoidally, with
semi-amplitude 268 +- 4 km/s, on the orbital period, which is refined to
0.198094(2) d. At this orbital period the secondary's spectral type is
atypically early, suggesting an unusual evolutionary history. We also obtained
BVI photometry around the orbit. The light curve resembles that given by Woudt
et al., and the color modulation is consistent with a heating effect. A simple
illumination model matches the observations strikingly well with a Roche-lobe
filling secondary near 5650 kelvin being illuminated by a primary giving out
around 2 solar luminosities. The modest amplitude of the observed modulation
constrains the orbital inclination to be less than about 55 deg, unless the
gravity darkening is artificially reduced. The resulting primary star mass is
above the Chandrasekhar limit (assuming conventional gravity darkening). We
examine the possibility that the compact object in this system is not a white
dwarf, in which case this is not actually a cataclysmic variable. On close
examination, FIRST J102347.6+003841 defies easy classification.
