Every murder happens at 3:16 AM. Every victim is powerful. Respected. And secretly monstrous. FBI profiler Park Ji-Hoon is assigned to stop the killer... but the deeper he digs, the more disturbing the pattern becomes. Because someone keeps leaving rose petals at every crime scene. And somehow... Ji-Hoon is the only one who notices them. Then he meets Y/N -a woman who photographs the city at 3:16 AM. She's calm around death. Too calm. And the closer Ji-Hoon gets to catching the killer... The more he begins to wonder if he's chasing the monster- or falling for it.