The Family Name (The Zero Enigma 9). The Zero Enigma, #9

House Rubén and House Aguirre had been rivals for centuries even before the discovery of the Zero Talent and a plot to take control of Shallot plunged them - and the entire city - into war.  In a desperate attempt to end the fighting, Akin of House Rubén was betrothed to the only known Zero, Caitlyn of House Aguirre.  Since then, the two houses have been locked in an uneasy alliance, painfully aware that they will hang separately if they do not hang together. But, as the marriage starts to loom over the city, Akin Rubén discovers a deadly secret.  His twin sister Isabella, sent into exile for her role in the House War, has discovered Callam, the second known Zero.  And Isabella's desire to carve a position for herself within the family, a role denied to her through no fault of her own, will shake House Rubén to its core.  As shadowy figures step into the light, ready to stake everything on a desperate bid to save or damn the family, Akin and Isabella find themselves in the middle of a deadly storm that may destroy everything they love ......
And plunge the city back into war.