  Observing programs comprising multiple scientific objectives will enhance the
productivity of NASA's next UV/Visible mission. Studying active galactic nuclei
(AGN) is intrinsically important for understanding how black holes accrete
matter, grow through cosmic time, and influence their host galaxies. At the
same time, the bright UV continuum of AGN serves as an ideal background light
source for studying foreground gas in the intergalactic medium (IGM), the
circumgalactic medium (CGM) of individual galaxies, and the interstellar medium
(ISM) and halo of the Milky Way. A well chosen sample of AGN can serve as the
observational backbone for multiple spectroscopic investigations including
quantitative measurements of outflows from AGN, the structure of their
accretion disks, and the mass of the central black hole.
