The main characters are ex-spouses with a kid. Their marriage didn't work because of the male lead's drinking, and the female lead was the only one taking care of their child. After the divorce, they did not remain friends, and every meeting from then on ended in a quarrel. The male lead is an officer and the female lead works with mass media. He's still jealous of his ex-wife, especially when she decides to marry a young man who helped her before. He didn't like the marriage of his ex-wife and quite by chance, he finds out that the new husband is not such an exemplary family man. Gathering the evidence, he tries to open her eyes, but she stubbornly doesn't want to take them into account. Only when the beloved began to implement his plan, she realized in what a dangerous situation she fell in, and the only one who came to her rescue was her ex.
(Source: MyDramaList)