Abstract: This talk opens with a summary of recent IceCube results establishing Seyfert galaxies as potential high-energy neutrino emitters, highlighting the role of neutrinos as unique messengers from the high-energy universe. The same dense coronal environments that make these sources efficient neutrino factories render them opaque to cosmic-ray escape, raising the question of where ultra-high-energy cosmic rays (UHECRs) are instead accelerated. The talk will also touch on the exciting prospects ahead, with next-generation observatories such as IceCube-Gen2 and P-ONE set to dramatically sharpen our view of the high-energy neutrino sky.