Clematis and the Queen of the Void by Hiyodori

"I’ve been your enemy before. I can be your enemy again."

Clematis and the Queen of the Void continues the Clem & Wist series with a horror-tinged saga of lovers to enemies (and back again). In this slow-burn f/f romance, devoted partners transform into devious adversaries—but opposition only serves to deepen their bond.

The best place to take a mage on vacation: a country without magic. As the most powerful mage in eons, Wist never gets much rest. That’s why Clematis drags her to an idyllic town in a land where all magic use has been made strictly illegal.

Charmed by the rural scenery and unusual wildlife, they initially find little cause for concern. The townspeople are welcoming, if rather eccentric. No one dwells on old rumors of vanishing mages. Or eerie myths about the local caves.

On the third day of their stay, Wist disappears without a trace. Impenetrable walls spring up around town. No one can enter, and no one can leave. The locals begin to whisper of an all-powerful and deeply beloved Queen who has ruled them for as long as anyone can remember. A magical Queen who sounds exactly like Wisteria Shien.

For reasons of her own, Wist has trapped the entire town in an eternal autumn. She won’t let time move forward, and she won’t let anyone escape her. Especially not Clem.

Yet Wist—now an invincible tyrant—might not realize that Clem needs neither magic nor allies nor even a sliver of hope to ferociously resist her rule. Truth be told, Clem has always loved having a nemesis.

The Clem & Wist Series
Prequel: No One Else Could Heal Her
Book 1: The Lowest Healer and the Highest Mage
Book 2: The Reverse Healer Case Files
Book 3: Clematis and the Queen of the Void

Each novel revolves around the same couple. The prequel can be read either before or after the rest of the series. (The prequel and Book 1 also work as satisfying standalone stories.)