The Borrowed Crown (en Inglés) - L F Vieira

The only clue is a ring of royal magic in Lysa's blood. It should belong to one man: King Cassian Valedryn, the immortal ruler who has kept his kingdom prosperous for more than a thousand years. Cassian insists he never touched Lysa. Worse, he appears to be telling the truth.

Their search leads beneath the Crown, into a medical conspiracy officially destroyed six centuries ago. Its victims are still alive. Its records bear Cassian's authority. And its next experiment is Mira herself.

Because when Mira touches the king, his immortality stops.

No borrowed years. No hidden victim. No one else paying for his life.

To save Lysa and forty-six other marked people, Mira and Cassian must trust the one person capable of taking away what each protects most: his kingdom, her sister, and the right to choose what happens to their own bodies.

But the closer they come to the truth, the more dangerous their attraction becomes-and the Crown's oldest secret is prepared to make love itself a weapon.