She walked past cells where inmates sat entranced by the flickering lights of TV screens or computer games. In other cells, they just lay there immobile on their bunks plugged into headphones listening to music or reading magazines.

To an outside observer, it might have seemed an easy life, but she sensed that it was all part of a desperate quest for distraction from the tedium and boredom of life in the prison. And more than that it was a way to avoid having to think too much about what they had done to end up behind bars in the first place.

As she walked along, she wondered how best to frame her approach to Melanie Clarke, how to broach the subject of Alice without sounding odd or raising suspicion. After all, she and Alice weren’t supposed to be connected to each other in any way whatsoever. In the end, she decided that she’d just play it by ear.

She reached cell number 113 and stepped into the open doorway. A white inmate with long brown hair was sitting cross-legged on the floor with her eyes closed in what appeared to be a meditative yoga position.

‘Melanie Clarke?’ said Bailey.

The inmate opened her eyes and looked at Bailey with a slightly miffed expression. She shook her head and nodded to her right. ‘She’s with her mates. Cell at the end. Follow your nose.’

She closed her eyes again.

Bailey stepped back onto the landing. She sniffed the air. The odour of illicit drugs was always present, but the distinctive smell of marijuana seemed to be particularly pronounced down here. She continued walking along the landing. As she drew closer to the cell at the end, the pungent smell of dope grew even stronger. As did the sound of music. She recognised the bass thump and reverb of heavy dub. It resembled some psychedelic form of reggae.

She stopped outside the last cell. The door was open. She peered in warily but it was hard to see anything through the thick layers of marijuana smoke. As her eyes adjusted to the dimness, the first thing she made out was the glowing tip of a joint as it flared and was passed around the three inmates occupying the cell.

Beneath a large poster of Jean-Claude Van Damme flexing his oiled muscles was a white inmate sitting on a chair at the desk rolling a joint. She had a nose ring and her dark red hair was twisted into crude dreadlocks. On the bunk was a mocha-skinned Asian inmate who was nodding her head hypnotically to the music emanating from the cheap portable stereo that was sitting by her feet. And slumped next to her on the bunk was a mixed-race inmate with her frizzy hair poking out in all directions. She was just staring vacantly into middle space.

Bailey wondered which one of the three was Melanie Clarke.

For some reason, there was a colourful profusion of small origami animals scattered around the cell. With a single glance, Bailey could distinguish a crane, a horse, a tortoise and what even appeared to be a spider.