Based on the British drama Doctor Foster; our main protagonist Ji Sun-Woo played by Kim Hee-Ae has it all. A beautiful home, a great career as a family practicing doctor, and a wonderful family. That is until she discovers her family, her friends, and her home isn't all too secure. The fickle people in Sun-Woo's life will have her picking between her sanity or keeping everything she has. This drama is extremely well written. I would suggest you watch the character's body language, their emotions, and not take anything they say literally. You will be confused if you do. Literally everything everyone does in this drama is for personal gain, and words do not coincide with actions. I would highly recommend, if you are looking for something close to this/just as mature watch Misty, Secret Affair, VIP, and or second 20 (a bit more lighthearted but about mature people and a affair).