  Q0056-363 is the most powerful X-ray quasar known to exhibit a broad, likely
relativistic iron line (Porquet & Reeves 2003). It has been observed twice by
XMM-$Newton$, three and half years apart (July 2000 and December 2003). In the
second observation, the UV and soft X-ray fluxes were fainter, the hard X-ray
power law flatter, and the iron line equivalent width (EW) smaller than in the
2000 observation. These variations can all be explained, at least
qualitatively, if the disc is truncated in the second observation. We report
also on the possible detection of a transient, redshifted iron absorption line
during the 2003 observation.
