  We present simultaneous XMM-Newton and NuSTAR observations of the repeat
changing-look AGN NGC 1566, which dramatically increased in brightness in the
IR to X-ray bands in 2018. The broad-band X-ray spectrum was taken at the peak
of the outburst and is typical of Seyfert 1 AGN. The spectrum shows a soft
excess, Compton hump, warm absorption and reflection, ruling out tidal
disruption as the cause of the outburst and demonstrating that a 'standard'
accretion disk can develop very rapidly. The high resolution grating spectrum
reveals that the outburst has launched a ~ 500 km/s outflow, and shows
photoionised emission lines from rest-frame gas. We discuss possible mechanisms
for the outburst, and conclude that it is most likely caused by a disk
instability.

High Energy Astrophysical Phenomena