  We report new (1995) Very Large Array observations and (1984 - 1999)
Effelsberg 100m monitoring observations of the 22 GHz H2O maser spectrum of the
Seyfert 2 galaxy NGC 1068. The sensitive VLA observations provide a
registration of the 22 GHz continuum emission and the location of the maser
spots with an accuracy of ~ 5 mas. Within the monitoring data, we find evidence
that the nuclear masers vary coherently on time-scales of months to years, much
more rapidly than the dynamical time-scale. We argue that the nuclear masers
are responding in reverberation to a central power source, presumably the
central engine. Between October and November 1997, we detected a simultaneous
flare of the blue-shifted and red-shifted satellite maser lines. Reverberation
in a rotating disk naturally explains the simultaneous flaring. There is also
evidence that near-infrared emission from dust grains associated with the maser
disk also responds to the central engine. We present a model in which an X-ray
flare results in both the loss of maser signal in 1990 and the peak of the
near-infrared light curve in 1994. In support of a rotating disk geometry for
the nuclear masers, we find no evidence for centripetal accelerations of the
redshifted nuclear masers; the limits are +/- 0.006 km/s/year, implying that
the masers are located within 2 degrees of the kinematic line-of-nodes. We also
searched for high velocity maser emission like that observed in NGC 4258. In
both VLA and Effelsberg spectra, we detect no high velocity lines between +/-
350 km/s to +/- 850 km/s relative to systemic, arguing that masers only lie
outside a radius of ~ 0.6 pc (1.9 light years) from the central engine
(assuming a distance of 14.4 Mpc).
