What Remains is a thrilling four-part whodunit set in a block of flats in South London, starring David Threlfall. Two years after her disappearance, the badly decomposed body of Melissa Young - a single woman in her early thirties - is discovered in the loft of her former apartment. How is it that no one missed her, or even noticed that she was gone? What does that say about the life she lived or the society we occupy? And what of her killer? Are they still at large?