The Last Days of Kira Mullan

Nancy North and her boyfriend, Felix, are making the move across London to a new flat, a new area, a new start. Because while Nancy is fine now, she wasn't fine before. But settling in isn't helped by Felix's hovering concern. She is all right. She is sticking to her breathing exercises and doctor-prescribed help. So, when their new neighbour Kira Mullan is found dead by suicide, Felix is understandably worried about Nancy's state of mind.
But Nancy saw Kira the day before she died and she didn't strike her as someone who was suicidal - she was upset and angry, yes, but enough to take her own life ? Nancy is the only one convinced that there's more to Kira's death than meets the eye. But all the police and the neighbours see is a vulnerable woman who isn't sure of what she saw, and might even be imagining things ... But what if Nancy is right ? Are there more questions that should be asked about the last days of Kira Mullan ?