The Nightmare's Kiss (Monster Research Facility Book 1)

Mara never thought she'd end up researching an actual monster. Everyone warns her that Subject X-13, “The Nightmare,” is dangerous. But when she falls for him, she'll have to risk everything to set him free... TNK is the 1st in a series but can be read as a standalone. It features a smart FMC, a shadow monster MMC, and open door spice. Free on KU!