Everline has devoted her life to the wardens - warriors who guard against monsters known as the vespertine. When a series of strange omens occur, Everline disobeys orders and sneaks out from the enclave to investigate. On the moorland, Everline meets Ravel Severin, a rogue vespertine. Everline knows...

Everline has devoted her life to the wardens - warriors who guard against monsters known as the vespertine. When a series of strange omens occur, Everline disobeys orders and sneaks out from the enclave to investigate. On the moorland, Everline meets Ravel Severin, a rogue vespertine. Everline knows she is sworn to kill Ravel, but when her best friend is captured, she makes the dangerous choice to ask for his help instead. Ravel agrees to assist her, but in exchange he demands a price - her blood. As Everline and Ravel travel further across the moorland, Everline realizes the question isn’t whether she will survive the journey, but if she will return unchanged - and if she wants to.