The phototaxis of living creatures — their instinctive response to light. After the death of Chairman Jeong Ilhwan of DS Group, the only one left by his side is his cherished young omega lover, Yu Cha-yeon. Determined to seize full control of the organization, Choi Taemu decides that taking even Jeong’s bonded partner as his own will solidify his power. But Cha-yeon isn’t what the rumors promised. Far from the mute seductress people describe, he seems strangely innocent—soft in a way Taemu can’t quite understand. And when Cha-yeon’s heat cycle begins, Taemu gives in to impulse…and sets their fates on a dangerous course.