  We present the results of a multi-epoch radio monitoring campaign measuring
the milliarcsecond structure of the jet in the radio-quiet quasar PG1407+263.
This is the highest-sensitivity, highest-resolution multi-year study of a
distant active galaxy. The observations are naturally explained in terms of a
beamed relativistic jet, some of whose fluctuations in flux density can be
ascribed to interaction with the narrow-line region of the quasar. The optical
properties of PG1407+263, in particular the low equivalent widths of the
emission lines, may be related to the fact that we are viewing this quasar
almost pole-on, giving us a direct view into its broad-line region.
