  We review what we have learnt with ASCA from studying the Fe-K lines in AGN
and describe a program to deconvolve the narrow, non-disk components of the
lines with Chandra. This is necessary to derive the correct profiles of the
broad, relativistic lines obtained using data from XMM and other
high-throughput instruments. Since reverberation techniques are now not looking
promising, we present Constellation-X simulations showing an alternative way we
might be able to measure black-hole mass and spin.
