  We present 1.8 years of near-daily Swift monitoring of the bright, strongly
variable Type 1 AGN Fairall 9. Totaling 575 successful visits, this is the
largest such campaign reported to date. Variations within the UV/optical are
well-correlated, with longer wavelengths lagging shorter wavelengths in the
direction predicted by thin disk/lamp-post models. The correlations are
improved by detrending; subtracting a second-order polynomial fit to the
UV/optical light curves to remove long-term trends that are not of interest to
this study. Extensive testing indicates detrending with higher-order
polynomials removes too much intrinsic variability signal on reverberation
timescales. These data provide the clearest detection to date of interband lags
within the UV, indicating that neither emission from a large disk nor diffuse
continuum emission from the broad-line region can independently explain the
full observed lag spectrum. The observed X-ray flux variations are poorly
correlated with those in the UV/optical. Further, subdivision of the data into
four ~160 day light curves shows that the UV/optical lag spectrum is highly
stable throughout the four periods, but the X-ray to UV lags are unstable,
significantly changing magnitude and even direction from one period to the
next. This indicates the X-ray to UV relationship is more complex than
predicted by the simple reprocessing model often adopted for AGN. A bowl model
(lamp-post irradiation and blackbody reprocessing on a disk with a steep rim)
fit suggests the disk thickens at a distance (~10 lt-day) and temperature
(~8000K) consistent with the inner edge of the BLR.
