  The quadruple system PG 1115+080 is the second gravitational lens with a
reported measurement of the Hubble constant. In addition to the primary lens,
three nearby galaxies are believed to contribute significantly to the lensing
potential. In this paper we report accurate redshifts for all four galaxies and
show that they belong to a single group at z_d = 0.311. This group has very
similar properties to Hickson's compact groups of galaxies found at lower
redshifts. We briefly discuss implications for the existing lens models and
derive H_0 = 52 +/- 14 km/s/Mpc.
