Our middle sister, Bethany, had offered to look after Ruby-May. Bethany’s good with children. She’s a TV presenter, so you can imagine that her over-the-top energy, disregard for rules and ability to perform on demand goes down well with small people. So that afternoon, as I was inching across the countryside, Brean Down a gleaming Arthurian mound in the distance, Blade Runner: The Director’s Cut playing on my iPhone, Amy, Matt, Lotte and Theo were in Street looking at shoes, and Bethany, Ruby-May and Dad were at The Pines. Dad is in his seventies now and is not as sprightly as he was. He spent most of the afternoon dozing on a wooden sun-lounger in the herb garden at the front of the house: it’s a real suntrap.

I should mention at this point that they weren’t the only people at The Pines. Matt’s teenage daughter, Chloe, from his previous marriage, was sunbathing next to Dad. After a while, she grew bored and went indoors – to do her homework, she said, but she was probably attempting to hook up with her friends over the lousy Internet connection. I found her half-empty glass of lemonade later, abandoned by the garden table, with a striped straw and a drowned wasp in it.

The only other person who was there that day was also inside. Luca – Amy and Matt’s ad-hoc childminder. The master’s degree he’s studying for is in child psychology, although I’m not sure how relevant that is, but his ability to relate to kids is probably why Ruby-May loved him so much. Matt has to leave the house by 7.30 a.m., and Amy has a part-time job as a charity fundraiser, so for three days a week Luca took Lotte and Theo to and from school, and looked after Ruby-May. I guess he’d have taken her to nursery that September, if things had turned out differently.

I learned all of this later. At the time I wouldn’t have known the minutiae of their daily lives and I’d never met Luca. I usually just turned up with sweets and caused chaos. That’s what uncles do, right? Anyway, Luca was there to celebrate Ruby-May’s birthday and maybe have a break from Bristol and enjoy the countryside. That morning he’d got up early and gone for a run.

At least, that’s what the police told me.

Luca is tall and rangy, and I imagine him loping through the dawn-stretched shadows across the dew-soaked fields. He said he spent the rest of the day in his room, studying.