The Silver Thread by Ema V. Arden

One near-fatal accident. One forbidden love. And a law that was never meant to be broken.

In the realm of A’aru, the Law of Oblivion is absolute. Guardians protect. Humans forget.
Alderian is an A’aruin, a guardian bound to Augustine by a glowing Silver Thread. For lifetimes, he has watched her from the edge of her world, remembering every version of her while she—like all of humanity—wakes each morning with a clean slate.

Until the night oblivion fractures.
After a near-fatal accident, Augustine remembers. For the first time, she doesn’t just feel a presence in the dark; she sees Alderian. She sees the Silver Threads linking every soul to its protector. And she sees the Shadows that have been waiting in the periphery, watching her with unsettling recognition.

Now, Augustine is an anomaly, a breach in an order that does not tolerate defiance.

The High Council is coming to erase her. The Shadows are closing in. And the only one who can keep her alive is the man she was never meant to see at all. To stay together, they must defy the laws of A’aru. To survive, they may have to let the world burn.