This is too long and not focused enough, but I can't see how to fix it.
In this 80,000 word urban fantasy, The Brigid, one man's lack of faith in his unseen heritage may be the weakness that destroys the entire world, starting with those closest to him.
They are brothers. Twins. They live in the white world, but a piece of them belongs to their mother's people, the Nez Perce. Caleb accepts that piece of himself, but Mika's doubts haunt him. In spite of what his brother thinks, it's intuition that sometimes guides Mika, not the spirit guide he courted in his adolescence.
Into their lives comes Brigid, a beautiful woman with no memory and enemies—and friends—who stretch the brothers' credulity. Creatures like the beautiful but terrifying Tuatha de dannan and the wee man who smokes a dragonbone pipe and who just might be a leprechaun. These creatures aren't even from their heritage, but the twins' spirit guides won't let turn their backs no matter how unbelievable all this is. They can't, because the magic that has been locked away in various pocket worlds for nearly two millennium is flooding back into the world through dangerously wide-open portals created by those who want to reclaim this world, but whose recklessness threatens to destroy everything in an explosive chain reaction. And behind it all, the dragons of Brigid's world laugh at how easy humankind is to manipulate.
In order to save not just the world of the mysterious stranger, who both brothers are starting to fall in love with, but their own world as well, Mika must learn to believe and Caleb must learn to see his own worth outside of his brother's shadow.
Thanks to anyone who has any ideas.