Episode 4

S1 E4: Clive Bonn is brought in for questioning, but his immoral motives for being at Hampstead Heath near Grace's burial site exonerate him from being the murderer. Maddy can't get hold of Adrian after their last fight and Peter is still pursuing her. He surprises her on her doorstep and walks her to her university. As she's about to leave, he gives her a gift-wrapped present, its significance will later be horrifically telling for Maddy. Laura and Rav question Marcella about why she was looking at CCTV from Grace's house, but Marcella manages to conceal the truth. She's told to look through it again for a minicab as one has been seen near two of the previous victims' houses. Laura pressures Marcella to give her DNA after blood is found at Grace Gibson's house. Marcella, realising that the blood is probably hers, devises a plan to avoid the truth coming out. Marcella's brilliant ability to deceive once again comes to the fore.