Something Wicked by Lily Morton

After powerful psychic Blue Billings fell in love with Levi Black, he believed their biggest challenges would arise from Blue’s ability to see and speak to the dead. So it’s rather alarming when he and Levi are confronted with a spate of new—and frightening—problems that have to do with the realm of the living.
A sadistic serial killer is stalking their beloved York, and Blue himself is in the killer’s crosshairs. Blue and Levi must race against time to catch the murderer as the deaths increase in ferocity. But when they’re forced from their home, and close acquaintances seemingly disappear like mist over the Minster’s spires, Blue finds that he is completely and terrifyingly on his own, and for the first time in his life, he’s without his powers.