  We present the discovery of a super lithium-rich K giant star, G0928+73.2600.
This red giant (T_eff = 4885 K and log g = 2.65) is a fast rotator with a
projected rotational velocity of 8.4 km/s and an unusually high lithium
abundance of A(Li) = 3.30 dex. Although the lack of a measured parallax
precludes knowing the exact evolutionary phase, an isochrone-derived estimate
of its luminosity places the star on the Hertzsprung-Russell diagram in a
location that is not consistent with either the red bump on the first ascent of
the red giant branch or with the second ascent on the asymptotic giant branch,
the two evolutionary stages where lithium-rich giant stars tend to cluster.
Thus, even among the already unusual group of lithium-rich giant stars,
G0928+73.2600 is peculiar. Using 12C/13C as a tracer for mixing---more mixing
leads to lower 12C/13C---we find 12C/13C = 28, which is near the expected value
for standard first dredge-up mixing. We can therefore conclude that "extra"
deep mixing has not occurred. Regardless of the ambiguity of the evolutionary
stage, the extremely large lithium abundance and the rotational velocity of
this star are unusual, and we speculate that G0928+73.2600 has been enriched in
both lithium and angular momentum from a sub-stellar companion.
