  We report the weak lensing discovery, spectroscopic confirmation, and weak
lensing tomography of a massive cluster of galaxies at $z=0.68$, demonstrating
that shear selection of clusters works at redshifts high enough to be
cosmologically interesting. The mass estimate from weak lensing, $11.1 +- 2.8 x
10^{14} (r/Mpc)$ solar masses within projected radius r, agrees with that
derived from the spectroscopy ($\sigma_v = 980 km s^{-1}$), and with the
position of an arc which is likely to be a strongly lensed background galaxy.
The redshift estimate from weak lensing tomography is consistent with the
spectroscopy, demonstrating the feasibility of baryon-unbiased mass surveys.
This tomographic technique will be able to roughly identify the redshifts of
any dark clusters which may appear in shear-selected samples, up to z ~ 1.
