The Prison Healer by Lynette Noni

At Zalindov, the only person you can trust is yourself.

Seventeen-year-old Kiva Meridan is a survivor. For ten years, she has worked as the healer in the notorious death prison, Zalindov, making herself indispensable. Kept afloat by messages of hope from her family, Kiva has one goal and one goal only: stay alive.

Then one day the infamous Rebel Queen arrives at the prison on death's door and Kiva receives a new message: Don't let her die. We are coming.

The queen is sentenced to the Trial by Ordeal: a series of elemental challenges against the torments of air, fire, water, and earth, assigned to only the most dangerous of criminals. Aware the sickly queen has little chance of making it through the Trials alive, Kiva volunteers to take her place. If she succeeds, both she and the queen will be granted their freedom.

But no one has ever survived.

And with an incurable plague sweeping Zalindov, a mysterious new inmate fighting for Kiva's heart, and a prison rebellion brewing, Kiva can't escape the terrible feeling that her trials have only just begun.

From bestselling Australian author Lynette Noni comes a masterful and action-packed YA fantasy perfect for fans of Sarah J. Maas and Sabaa Tahir.