  We present results from a short {\em Chandra}/ACIS-S observation of NGC 7618,
the dominant central galaxy of a nearby ($z$=0.017309, d=74.1 Mpc) group. We
detect a sharp surface brightness discontinuity 14.4 kpc N of the nucleus
subtending an angle of 130$^\circ$ with an X-ray tail extending $\sim$ 70 kpc
in the opposite direction. The temperature of the gas inside and outside the
discontinuity is 0.79$\pm$0.03 and 0.81$\pm$0.07 keV, respectively. There is
marginal evidence for a discontinuous change in the elemental abundance
($Z_{inner}$=0.65$\pm$0.25,$Z_{outer}$=0.17$\pm$0.21 at 90% confidence),
suggesting that this may be an `abundance' front. Fitting a two-temperature
model to the ASCA/GIS spectrum of the NGC 7618/UGC 12491 pair shows the
presence of a second, much hotter ($T$=$\sim$2.3 keV) component. We consider
several scenarios for the origin of the edge and the tail including a radio
lobe/IGM interaction, non-hydrostatic `sloshing', equal-mass merger and
collision, and ram-pressure stripping. In the last case, we consider the
possibility that NGC 7618 is falling into UGC 12491, or that both groups are
falling into a gas poor cluster potential. There are significant problems with
the first two models, however, and we conclude that the discontinuity and tail
are most likely the result of ram pressure stripping of the NGC 7618 group as
it falls into a larger dark matter potential.
