Her first instinct was to arrive right on time at the rendezvous, an anonymous terraced house in Stoke Newington. But that might be the first test in itself. Perhaps she was supposed not to do what was expected of her. Hurriedly, she showered and dressed in the clothes she’d decided Janine Jerrold would have worn for such an assignment. A short black lycra skirt, a white T-shirt with long sleeves and a scoop neck under a fitted fake leather jacket. In her shoulder bag she carried everything she needed to change her look. A baseball cap, aviator frames with clear glass lenses, a pair of denim leggings and a lightweight waterproof kagoule in a nasty shade of pale blue. Also in the shoulder bag was an illegal CS gas spray and a metal comb with a sharpened tail. They were both relics of her days in CID in the port of Seaford, items she’d confiscated and never got round to handing in. She wasn’t quite sure how her watchers would react if she had to resort to them, but she was supposed to be showing initiative and acting like a real drugs courier. She could always argue the point afterwards.

Having decided to arrive early, Carol set out from her flat just after eight. She took a circuitous route to her destination. There would, she was sure, be followers, but she had no intention of making it easy for them. Taking advantage of the rush-hour commuters would be one way of improving her edge. Even so, she still jumped off the tube at the last possible moment, doubling back three stops before emerging at street level and catching a bus.

When she turned into the quiet side street, there was no one on her heels. But that didn’t mean there weren’t keen eyes on her. She climbed the three steps to the front door she’d been directed to. The paintwork was filthy with London grime, but it looked in reasonably good condition. She pressed the doorbell and waited. Long seconds passed, then the door opened a couple of inches. A pale face smudged with stubble and topped with a spiky crest of black hair peered at her. ‘I’m looking for Gary,’ she said, as instructed.

‘Who are you?’

‘Jason’s friend.’ Again, following her orders.

The door swung open, the man taking care to stay out of sight of the street as he let her in. ‘I’m Gary,’ he said, leading the way into the front room. He was barefoot, wearing faded 501s and a surprisingly clean white T-shirt. Dingy net curtains hung at the window, obscuring the street. The carpet was an indeterminate shade between brown and grey, worn almost to the backing in front of a sagging sofa that faced a wide-screen NICAM TV complete with DVD player. ‘Take a seat,’ Gary said, waving a hand at the sofa. It wasn’t an appetizing prospect. ‘I’ll be right back.’