Throne of Ice and Blood by Marion Blackwood

After the Atonement Trials, Selena is trying to navigate her new life outside the Seelie Court. The world is very different from what she imagined, but her mission remains the same. Using every skill she has, she is going to help the secret resistance take down the Iceheart Dynasty.
But that path yet again sets her on a collision course with Draven Ryat. While the rebellion plots a daring scheme, important people start turning up dead. Draven is tasked with solving the murders. Selena is trying to help the killer. If either one of them fails, they will face dire consequences.
When blood stains the ice and dangerous secrets are brought to light, Selena must decide if she is willing to doom Draven in order to achieve her own goals. After everything that has happened between them, their relationship is already complicated. But now, with their very lives on the line, their tangled feelings for each other might destroy them both.