  We present the first detailed abundance analysis of the metal-poor giant HKII
17435-00532. This star was observed as part of the University of Texas
long-term project "Chemical Abundances of Stars in the Halo" (CASH). A spectrum
was obtained with the High Resolution Spectrograph (HRS) on the Hobby-Eberly
Telescope with a resolving power of R~15,000. Our analysis reveals that this
star may be located on the red giant branch, red horizontal branch, or early
asymptotic giant branch. We find that this metal-poor ([Fe/H]=-2.2) star has an
unusually high lithium abundance (log eps (Li)=+2.1), mild carbon ([C/Fe]=+0.7)
and sodium ([Na/Fe]=+0.6) enhancement, as well as enhancement of both s-process
([Ba/Fe]=+0.8) and r-process ([Eu/Fe]=+0.5) material. The high Li abundance can
be explained by self-enrichment through extra mixing that connects the
convective envelope with the outer regions of the H-burning shell. If so, HKII
17435-00532 is the most metal-poor star in which this short-lived phase of Li
enrichment has been observed. The Na and n-capture enrichment can be explained
by mass transfer from a companion that passed through the thermally-pulsing AGB
phase of evolution with only a small initial enrichment of r-process material
present in the birth cloud. Despite the current non-detection of radial
velocity variations (over ~180 days), it is possible that HKII 17435-00532 is
in a long-period or highly-inclined binary system, similar to other stars with
similar n-capture enrichment patterns.
