  NGC 3227 exhibits rapid flux and spectral variability in the X-ray band. To
understand this behaviour we conducted a co-ordinated observing campaign using
320 ks of XMM-Newton exposures together with 160 ks of overlapping NuSTAR
observations, spanning a month. Here, we present a rapid variability event that
occurs toward the end of the campaign. The spectral hardening event is
accompanied by a change in the depth of an unresolved transition array, whose
time-dependent behaviour is resolved using the RGS data. This UTA fingerprint
allows us to identify this as a transit event, where a clump of gas having NH ~
5 x 10^22 atoms/ cm^2, log xi ~2 occults ~60% of the continuum photons over the
course of approximately a day. This occulting gas is likely associated with
clouds in the inner BLR. An additional zone of gas with lower column and higher
ionization, matches the outflow velocity of the variable zone, and may
represent transmission through the cloud limb.
