  The isotopically chiral molecular ion CHDBrI$^+$ is identified as an
exceptionally promising candidate for the detection of parity violation in
vibrational transitions. The largest predicted parity-violating frequency shift
reaches 1.8 Hz for the hydrogen wagging mode which has a sub-Hz natural line
width and its vibrational frequency auspiciously lies in the available laser
range. In stark contrast to this result, the parent neutral molecule is two
orders of magnitude less sensitive to parity violation. The origin of this
effect is analyzed and explained. Precision vibrational spectroscopy of
CHDBrI$^+$ is feasible as it is amenable to preparation at internally low
temperatures and resistant to predissociation, promoting long interrogation
times (Landau et al.). The intersection of these properties in this molecular
ion places the first observation of parity violation in chiral molecules within
reach.
