I hurried across to the table and, as I did, remembered a moment, just before Mills had exited the cottage, when he’d picked up the phone. At the same time as he’d done that, I’d looked down at Healy, lying still, blood on his face, and had wondered what was going on, why Mills wouldn’t admit that he knew who Healy was.

I’d looked away for a second.

I stopped next to the table, staring at what Mills had left behind. There was no writing on the front of the envelope and, when I turned it over, I could see that it had been properly sealed. I glanced at Healy, asleep again now, unaware of any of this, and then scanned the rest of the living room, shadows still clinging to every surface. Was this legitimate? Or was it all part of the same trick?

As soon as I scooped up the envelope, I could feel something solid shifting inside, sliding from one end to the other, and knew straight away what it was.

A key.

I ripped open the seal.

The key’s design was unusual: it had the familiar lines on the blade but was moulded entirely from hard plastic. It was also extremely thin – perhaps only two millimetres in width – and had a tiny magnetic square at the point of the key. Whatever door it opened, the lock on that door was using a mixture of technologies – part tumbler, part electronic reader.

There was something else in the envelope too.

A folded piece of paper.

It was headed, crowned with a now familiar company logo and an address in York. Below that, handwritten in the middle of the page, were six numbers: 459822. I looked from those to the key – and a dizzying surge of adrenalin hit me.

The key was for Seiger and Sten’s office.

The numbers were their alarm code.

Martina: Part 1

1985

Los Angeles | Monday 5 August

The property was a single-family tan stucco with a raised porch, a bay tree in the yard and a rust-eaten fence between the sidewalk and the lawn. A brick driveway ran along one side of the building to a garage.

As soon as Jo pulled up outside, she could hear the low drone of the freeway; a slanted bank opposite the house, and a high concrete wall – its surface peppered with the ghosts of old graffiti – were the only things lying between the houses and the lanes of the 710. The moment she switched off the ignition, it got even louder, a perpetual wall of vehicle noise from which there would never be an escape, even in the dead of night.