Cassandra Clare

Cassandra Clare built one of young-adult fantasy's largest ongoing universes almost by accident — she was writing entertainment journalism in New York before her 2007 debut, City of Bones, grew into The Mortal Instruments, the six-book series that introduced Shadowhunters: warriors who hunt demons in a modern world hiding in plain sight of angels, vampires and warlocks. From there the Shadowhunter Chronicles kept expanding outward in both directions — backward into Victorian London with The Infernal Devices, forward into a generation of Mortal Instruments characters' children with The Dark Artifices, and further still with The Last Hours, a direct sequel to Infernal Devices following the next generation of that Victorian cast. Clare, who spent an itinerant childhood traveling internationally with her family before settling into writing, favors morally gray found-family casts, tangled love triangles and a mythology dense enough to reward readers who commit to the long haul across series. New readers should start with City of Bones, the entry point the whole franchise builds outward from, though Infernal Devices is frequently cited by longtime fans as the emotional high point. The Mortal Instruments was adapted into a 2013 film and the 2016-2019 Shadowhunters television series. Clare continues to expand the Chronicles, with a new trilogy, The Wicked Powers, due to begin in late 2026.