  A detailed high-resolution spectroscopic analysis is presented for the
carbon-rich low metallicity Galactic halo object CS 22964-161. We have
discovered that CS 22964-161 is a double-lined spectroscopic binary, and have
derived accurate orbital components for the system. From a model atmosphere
analysis we show that both components are near the metal-poor main-sequence
turnoff. Both stars are very enriched in carbon and in neutron-capture elements
that can be created in the s-process, including lead. The primary star also
possesses an abundance of lithium close to the value of the ``Spite-Plateau''.
The simplest interpretation is that the binary members seen today were the
recipients of these anomalous abundances from a third star that was losing mass
as part of its AGB evolution. We compare the observed CS 22964-161 abundance
set with nucleosynthesis predictions of AGB stars, and discuss issues of
envelope stability in the observed stars under mass transfer conditions, and
consider the dynamical stability of the alleged original triple star. Finally,
we consider the circumstances that permit survival of lithium, whatever its
origin, in the spectrum of this extraordinary system.
