Picks up a marker pen and adds handwritten notes to the timeline.

One was at 9.46 a.m., and lasted one minute twenty seconds; the number was listed to a local dry-cleaning firm, who later confirmed that they’d called to say Caroline’s cleaning was ready to collect. Luke answered the phone, and again, he apparently seemed perfectly normal.

The second call was at 2.37 p.m., and lasted two minutes thirty-three seconds, and was from a payphone. The police established that the phone in question was on the King’s Cross station concourse, but were never able to identify the caller.

HUGO FRASER

That’s too long for a wrong number.

BILL SERAFINI

I agree.

LAILA FURNESS

Was Luke alone in the house at the time?

BILL SERAFINI

Good question, hold that thought.

Meanwhile, back to the timeline: Caroline comes back from dropping off Guy at school at 9.15, then is in the house until 11.15, when she goes out to run some errands and then go for lunch. She confirmed that Luke was in the house that whole time, and, again, seemed perfectly normal. Nor did Beatriz Alves notice any tension between them, but she probably wasn’t in the same room very much, since she was cleaning and doing laundry.

(turns to the timeline again)

Caroline gets back from lunch at around 2.45; again, Luke seemed fine, and certainly doesn’t mention the mystery call from King’s Cross station. She goes out again at 3.30, first to collect her dry cleaning, which was confirmed by the police, and then pick up Guy from school.

In the meantime Maura and Amelie get back home around 4.15, and get changed before heading out to a party thing at one of their friend’s.

LAILA FURNESS

(smiling)

‘Party thing’? I can tell you don’t have kids.

BILL SERAFINI

(grinning back)

Is it that obvious? Anyway, there were a dozen or so girls at this whatever-you-call-it, and Maura and Amelie were there until around 7.

CAMERA TRACKS Bill as he turns and pins up a series of PHOTOS next to the timeline; Maura and Amelie are shown with several other teenage girls in a bedroom: fairy-lights around a mirror, a dressing-table stacked with make-up and nail varnish, a dreamcatcher on the wall, a scatter of brightly coloured cushions just visible on the bed.

The girls are making faces at the camera, striking poses, and taking turns wearing a pink Stetson, a lime-green feather boa, and various pairs of high-heeled shoes while they experiment with different make-up and hairstyles. They’re obviously having a whale of a time.

The girls get back to Dorney Place around 7.15, and have pizza in the kitchen with Luke and Guy.

HUGO FRASER

Who have presumably been at home that whole time.

BILL SERAFINI

Yeah, either in the garden or watching TV inside. There’d been heavy rain that morning but it was sunny in the afternoon, and Luke played cricket in the garden with Guy for an hour or so. At least until it got dark.

LAILA FURNESS

Sounds like Caroline wanted the two of them out from under her feet. Especially if she was going out that evening.