A killer only has to do three things. Go on missions. Kill people. Leave absolutely no trace behind. Joo Taeman has 14 years of experience under his belt and he’s never let his feelings get the better of him. Never. That is, until Taeman experiences butterflies in his stomach after seeing national sweetheart Kang Dahyeok in person. But as it turns out, Taeman’s not the only one smitten on the spot.