Cassie and Sunny discover Walsh was chased by all four suspects on the night in question. Willets realises Fiona's blood sample may have been deliberately lost by Liz. The pathologist identifies a cause of passing implying Walsh was cuddled.
Nicola Walker and Sanjeev Bhaskar star as detectives investigating a 'cold' cuddle case of 39 years ago.
When the bones of a young man are found beneath the footings of a demolished house, an investigation begins that will unravel the lives of four people who have been waiting for this moment for nearly forty years, as they discover that the past can't, and won't, stay buried forever.
Unforgotten - Series 4, Episode 4 Synopsis and Schedule