Trajectory of a photon that comprises a power-law event along with the black hole and the accretion disk (orange) when seeing the disk face on (left panel) and edge on (right panel). The line colors show the energy at infinity of the photon after being launched (1.7 keV, thin blue line), scattering once (0.7 keV, dotted green line), twice (28.6 keV, dashed yellow line), and three times (28.8 keV, thick red line). The first two scatterings occur within the ergosphere shown in gray.