The $B_s$ system is analyzed in light of a possible width difference
$\Delta\Gamma_s$ between its mass eigenstates. If $\Delta\Gamma_s$ is
sizable, untagged $B_s$-meson decays may allow a probe of CP
violation and moreover the extraction both of the Wolfenstein parameter
$\eta$ and of the notoriously difficult to measure angle $\gamma$ of
the unitarity triangle. To accomplish this ambitious task, time-dependent
angular distributions for untagged $B_s$ decays into admixtures of CP
eigenstates and channels that are caused by $\bar b\to\bar c u\bar s$
quark-level transitions play a key role. The work described here was
done in collaboration with Isard Dunietz.