To Kill a King by C.S. Wilde

The Night King is dead, and his killer is on the loose.
When Mera Maurea goes to Lunor Insul to investigate the Night King’s murder, she knows bringing her partner Sebastian Dhay is a mistake, mostly because he’s the victim’s freaking son.

Things would be a lot easier if Bast’s relationship with his four brothers wasn’t so… explosive. As the culprit keeps attacking the Night Court, Mera and Bast will have to catch him before all remaining Dhays are dead.

Everything is connected, and solving this case might just bring Mera closer to Poseidon.