In 1761, Tristan Kelly is one of six children to survive a mysterious fever aboard a ship bound for the Americas. Ever since, she has aged very slowly. She might be over two hundred years old, but she looks forty.

When Tristan hires Olivia Bryce as a new intern at her art restoration company, an unexpected attraction ignites which Tristan can't permit. The truth must never be revealed. Despite Tristan's resolve, their feelings grow when Tristan brings Olivia to Paris to work on a priceless painting at the Louvre. There, an old friend brings disturbing news: someone is hunting her, and all those who survived the fever, killing them one by one.

As Olivia begins to unravel the truth and the assailants get closer, Tristan and Olivia grow closer, too. Tristan knows there's no future for them and is ready to sacrifice herself to keep Olivia out of the crossfire. But Olivia refuses to listen to Tristan's arguments, insisting their love is fated and they must face the endgame together, no matter the consequences.