The Mark of the Phoenix — Casper Graham

Edwin Barrett is a phoenix shifter who protects other supernatural beings. A siren comes on land to lure men and women to their deaths. Believing Baltic Pelagius to be that siren, he attempts to annihilate him. He's thwarted by Drake Pelagius and Caspian Pelagius. The Pelagius brothers are identical triplets, but he only has eyes for Drake, who convinces him of Baltic's innocence. They work together to find the siren responsible for those deaths and investigate the reason for several merpeople missing from the Pacific Ocean. Drake doesn't expect the strength of his attraction toward Edwin. Agreeing to date Edwin is wonderful. Getting mated to Edwin is even better. As a merman, mating is meant to last for an eternity. His life is supposed to be peaceful and calm, but neither he nor Edwin can rest until their duties are done. Multiple dangers lurk just around the corner. Will they ever acquire the happy ending they yearn for?