A Shatter of Spells. The Resonant Arcana, #4

Fractured magic. Unraveling threads. The more they fight, the more everything falls apart. Vesper Ainsley's Resonant power has become both her greatest weapon and her most dangerous vulnerability. Now she faces her most impossible challenge yet - shadow magic spreads across Nightreach, the Threads are unraveling, and Lucian D'Arco grows ever closer to harnessing the Echo's devastating power. Joined by Rafe, whose own magical connection grows deeper with each passing moment, and Detective Blair Calloway, whose street-smart determination matches her investigative skills, Vesper must navigate a city on the brink of magical collapse.
The Concordat's defences are crumbling, magical practitioners are vanishing, shadow constructs overrun the streets, and the lines between ally and enemy blur with each passing hour. As ley lines fracture and shadow magic spreads like a poison through Nightreach, Vesper realises that stopping Lucian will require more than just power-it will demand a sacrifice she may not be prepared to make. With enemies closing in and the Echo's fragments calling to her, she must choose between saving herself or saving everything she loves.
For fans of intricate magical systems and high-stakes urban fantasy, A Shatter of Spells plunges deeper into a world where magic is both a weapon and a curse, and the cost of survival is never simple.