  We report results from a panoramic spectroscopic survey of 955 objects in the
field of the rich cluster Cl 0024+1654 (z~0.4), complementing the HST imaging
presented in the first paper in this series. Our new spectroscopic sample
includes over 200 high quality spectra of cluster members, spread across an
area 10 Mpc in diameter. We examine the properties of a large sample of 104
cluster early-types as a function of cluster radius and local density, using
them as sensitive tracers of the various physical processes that may be
responsible for galaxy evolution. By constructing the Fundamental Plane of Cl
0024, we infer an evolution in the mean mass to light ratio of early-types
equal to \Delta<Log (M/L_V)> = -0.14 +- 0.02. In the cluster center, we detect
a significantly increased scatter in the relationship compared to that seen in
local clusters. Moreover, we observe a clear radial trend in the mass to light
ratios of individual early types, with the oldest galaxies located in the
cluster core. Galaxies are apparently younger at larger radius, with E+S0s in
the periphery having M/L_V ratios that nearly match values seen in the field at
a similar redshift. Independent spectral indicators used in combination reveal
an abrupt interaction with the cluster environment which occurs near the virial
radius of Cl 0024, revealed by small bursts of star formation in a population
of dim early-types, as well as by enhanced Balmer absorption for a set of
larger E+S0s closer to the cluster core. We construct a simple infall model
used to compare the timescales and strengths of the observed interactions in
this cluster. We examine the possibility that bursts of star formation are
triggered when galaxies suffer shocks as they encounter the intra-cluster
medium, or by the onset of galaxy harassment.
