From the #1 New York Times bestselling author of These Violent Delights and Our Violent Ends comes the "equal parts intoxicating and dazzling" (Roshani Chokshi, New York Times bestselling author of The Gilded Wolves) first book in a captivating new duology following an ill-matched pair of spies posing as a married couple to investigate a series of brutal murders in 1930s Shanghai.

It's 1931 in Shanghai, and the stage is set for a new decade of intrigue.

Four years ago, Rosalind Lang was brought back from the brink of death, but the strange experiment that saved her also stopped her from sleeping and aging-and allows her to heal from any wound. In short, Rosalind cannot die. Now, desperate for redemption for her traitorous past, she uses her abilities as an assassin for her country.

Code name: Fortune.

But when the Japanese Imperial Army begins its invasion march, Rosalind's mission pivots. A series of murders is causing unrest in Shanghai, and the Japanese are under suspicion. Rosalind's new orders are to infiltrate foreign society and identify the culprits behind the terror plot before more of her people are killed.

To reduce suspicion, however, she must pose as the wife of another Nationalist spy, Orion Hong, and though Rosalind finds Orion's cavalier attitude and playboy demeanor infuriating, she is willing to work with him for the greater good. But Orion has an agenda of his own, and Rosalind has secrets that she wants to keep buried. As they both attempt to unravel the conspiracy, the two spies soon find that there are deeper and more horrifying layers to this mystery than they ever imagined.