  We introduce the first g-mode pulsator found to reside on the classical blue
horizontal branch. One year of Kepler observations of KIC 1718290 reveals a
rich spectrum of low-amplitude modes with periods between one and twelve hours,
most of which follow a regular spacing of 276.3 s. This mode structure strongly
resembles that of the V1093Her pulsators, with only a slight shift towards
longer periods. Our spectroscopy, however, reveals KIC 1718290 to be quite
distinct from the sdB stars that show V1093Her pulsations, which all have
surface gravities higher than log g = 5.1 and helium abundances depleted by at
least an order of magnitude relative to the solar composition. We find that
KIC1718290 has T_eff = 22 100K, log g = 4.72, and a super-solar helium
abundance (log N(He)/N(H) = -0.45). This places it well above the extreme
horizontal branch, and rather on the very blue end of the classical horizontal
branch, where shell hydrogen burning is present. We conclude that KIC 1718290
must have suffered extreme mass loss during its first giant stage, but not
sufficient to reach the extreme horizontal branch.
