Panel a: observed continuum light curve from Bentz et al. (2021) (black points) with the finer sampled interpolated continuum light curve over-plotted (grey line). Panel b: observed broad emission-line light curve (black points) with the emission-line light curve produced by reverberating the input continuum light curve off the clouds in our best-fit BLR model (red). Panel c: cross-correlation function between the continuum and broad emission-line light curves as a function of time-lag. The dashed line indicates the peak cross-correlation time-lag of 10.2 days.