  We present near-infrared spectra of ``A2'', the primary counter arc to the
gravitationally lensed galaxy MS1512-cB58. The spectra showredshifted H-alpha,
[NII], [OIII], and H-beta at z=2.728 +/- 0.001. We observe the same
H-alpha/[OIII] ratio as cB58, which together with the redshift confirms that A2
is indeed another image of a single background galaxy. Published lensing
reconstruction reports that A2 is a magnification of the entire source, while
cB58 is an image of only a part. At marginal significance, A2 shows higher line
to continuum ratios than cB58 (by a factor of about 2), suggesting a
non-uniform ratio of young to old stars across the galaxy. We observe a second
emission line source in the slit. This object, ``W5'', is predicted to be a
lensed image of another galaxy at a redshift similar to cB58. W5 is blueshifted
from cB58 by about 400 km/s and has a significantly lower H-alpha/[OIII] ratio,
confirming that it is an image of a different background galaxy in a group with
cB58. The H-alpha emission line in W5 implies a star formation rate of 6
Msun/yr (H_0 = 70 km/s/Mpc, Omega_M=0.3, Omega_L=0.7), after correcting for
lensing magnification.
