Eva, a cold-blooded assassin, accidentally triggers a deadly curse after killing the man chosen as her soulmate. Her only chance of survival is Leo—a clumsy Cupid apprentice who has failed his divine exam for ten thousand years. Bound by an invisible life thread, they must stay within three meters of each other or die. With only seven days left, the mismatched pair is forced to run from a powerful assassin organization while uncovering a conspiracy that has been manipulating love itself. Eva has never trusted anyone. But when Leo repeatedly risks his life to save hers, she must decide whether love is her greatest weakness—or her only way out.