Resonance

"In 'Resonance,' follow NIS agents Lee Suyeon and Jung Jaehyun as they navigate a world of covert operations, familial mysteries, and the delicate dance of love amidst the shadows of their past. A successful mission leads to celebrations and revelations, but the couple soon finds themselves entangled in a global conspiracy that tests their resilience and the strength of their bonds. As they face the echoes of their own hearts and confront a shadowy organization, the lines between duty and personal sacrifice blur. Will they unravel the mysteries that bind their destinies, or will the shadows prove too dark to escape?"

Sort of similar to Mingyu's book, 'Missing'