  We report the detection of a rapid occultation event in the nearby Seyfert
galaxy NGC 6814, simultaneously captured in a transient light curve and
spectral variability. The intensity and hardness ratio curves capture distinct
ingress and egress periods that are symmetric in duration. Independent of the
selected continuum model, the changes can be simply described by varying the
fraction of the central engine that is covered by transiting obscuring gas.
Together, the spectral and timing analyses self-consistently reveal the
properties of the obscuring gas, its location to be in the broad line region
(BLR), and the size of the X-ray source to be ~25 rg . Our results demonstrate
that obscuration close to massive black holes can shape their appearance, and
can be harnessed to measure the active region that surrounds the event horizon.
