Who was it? He’d initially thought Morag, or possibly Sonali, the bride-to-be who had unexpectedly arrived at the wake. But Harry hadn’t known her long. So perhaps it was Morag after all. She he had known for a decade. She who had been barred from becoming his wife.

Then Gillard heard a voice calling from within – Morag’s distinctive and delicious Scottish burr, asking: ‘Do you both want another drink? I’ve got Kiki a coffee, and she is happy to come and stay at mine, to leave you two in peace.’

You two? His mind reeled as he tried to figure out who it was that Harry had been embracing, if not Morag.

‘I’ll have a Glenfiddich,’ Harry answered, his flattening voice indicating he was making his way back into the flat. ‘We’re coming in, it’s getting a bit chilly.’ The detective could feel as much as hear the slide and thud of the glass door, and the more muffled sound of music. Waterloo by Abba.

The detective risked looking over the edge onto the now empty balcony. He was already out of order. He had, a week or so ago, gained a warrant for the family’s phones, but the terms made it clear that this was confined to looking at messages and contacts two days either side of Mrs Roy’s murder. He had no warrant for entering Harry’s home, and though he could legally track the family’s phones and the phone metadata, he was not entitled to look at their texts or emails outside the narrow time window stipulated in the warrant.

But he just had to know who that person was. It was a five-foot drop onto the edge of the balcony and, if he got his footing wrong – well, over a hundred feet down to the pavement below. He had never been afraid of heights, and was an experienced rock climber, but part of that was knowing when not to do something stupid. His black work shoes had barely any grip, and the top of the stainless steel balcony rail was curved and damp. He could get down there no trouble, but getting back was another story. Perhaps there was another way.

He got out his iPhone, turned the flash off, then crept right to the edge, above the sliding doors into the apartment. He crouched down and stretched his arm down as far as he could without over-balancing. He took a picture. He judged that there would be a view through the window into the flat, so long as they hadn’t drawn the curtains.

When he finally got to his knees and was able to examine the photo, he saw the fourth person in the room. And he was staggered.

Chapter 19

Suddenly it all made sense. Gillard scrambled back over the railing, back into the building and took a lift to the ground floor. He’d been wrong, so utterly and completely wrong. The Roy family had produced a brilliant feint. The implications were staggering.