  The star HII 2407 is a member of the relatively young Pleiades star cluster
and was previously discovered to be a single-lined spectroscopic binary. It is
newly identified here within $Kepler$/$K2$ photometric time series data as an
eclipsing binary system. Mutual fitting of the radial velocity and photometric
data leads to an orbital solution and constraints on fundamental stellar
parameters. While the primary has arrived on the main sequence, the secondary
is still pre-main-sequence and we compare our results for the $M/M_\odot$ and
$R/R_\odot$ values with stellar evolutionary models. We also demonstrate that
the system is likely to be tidally synchronized. Follow-up infrared
spectroscopy is likely to reveal the lines of the secondary, allowing for
dynamically measured masses and elevating the system to benchmark eclipsing
binary status.
