The Reanimator's Remains - The Reanimator Mysteries, #3

An autistic necromancer, his undead love, and a covenant that must be broken.  Oliver Barlow never knew what happened to his parents. With a note from his mother as his only lead, Oliver had given up hope of ever learning the truth. But when the dead start rising in the town of Aldorhaven, Oliver jumps at the chance to take the case if it means he can investigate the last place his parents were seen alive. Felipe Galvan would like to be anywhere but Aldorhaven.
Between protecting Oliver and Gwen, dealing with distrustful townsfolk, and an unexpected letter from his estranged parents, Felipe is already stretched thin. But when he is suddenly plagued by whispers from the woods and nightmares from his past, Felipe fears he is only one misstep away from becoming the monster he was meant to be. Far more sinister things than the dead lurk in Aldorhaven's woods.
A centuries old bargain has been broken, and the only thing that can satisfy it is Oliver's blood. Together, Oliver, Felipe, and Gwen must finish what Oliver's parents started, or they too will be ensnared by their devil's bargain.