The fire in the title is an event in the past that decimated the world, killing many. A few hundred years later, people all still alive, but as a strange side effect, everyone is now born as twins. One twin, the Alpha, is perfectly normal, but the other – the Omega – has some sort of defect. It’s usually evident, but in rare cases, the Omega is a seer, outwardly normal, but cursed with terrible visions that will eventually drive them mad. They’re separated at an early age – the Omegas sent to live on the outskirts of Alpha society. However, the Omegas have one advantage that keeps them from being persecuted too badly – when one twin dies, the other one will too.
Cass is the Omega, and a seer, but realizes from a very early age that she must hide her gift. Because they’re not separated, her twin, Zach, though he is fond of her in his own way, is so resentful that it warps him. When they’re finally separated, he embarks on some nasty plans to rid the world of Omegas. Cass is imprisoned in a facility where Alphas who have made enemies can keep their Omegas to keep them safe. She escapes with another inmate, and they journey to find a place where Omegas can live freely.
I really think this post apocalyptic thing is starting to get played out. This story has a few twists, the twins being the biggest, but the rest of it is that same depressing “young people against bad people who’ve found old technology and are using it for evil” trope that I’m getting a little tired of. This is the first book in a trilogy, but I’m not sure I’ll seek out the other two.