In the night of a glamorous jewel exhibition opening in Bangkok, a gun shot rings out. A young man and a young woman, who are reaching toward climax of life, are facing critically each other across the gun shot. Han Youngwon loses her fiance during the shot and Jung Sero is the one who is blamed for murdering Youngwon's fiance. Five years later, Sero, who has got a new life with a new name, and Youngwon, a cold-hearted meet again. Those two seems to have crossed the Rubicon, but Sero floats his boat with an intense feeling of 'revenge'. Believing that at the end of the Rubicon, there will be the 'Doom' of those two who have destroyed his life, Han Youngwon and her jewelry brand, Belle la Fair. However, at the end of the Rubicon that Sero tries to cross, there is no fury, hatred, or revenge, but only love. Will they get over 'a tragedy of the night' and forgive each other?