It was half past two on Friday afternoon when SG4 Tina Boyd stopped outside the Lively Lounge Club and Casino, a turd-coloured slab of a building straight out of the 1960s school of bland architecture, which sat at the Colindale end of the Edgware Road, about three miles and a thousand years as the crow flies from the leafy Hampstead suburb where Pat Phelan now lived. Looking at it made her feel mildly pleased that gambling wasn't one of her vices. It wasn't that she wasn't interested. She just didn't dare place a bet, even on something like the Grand National, because she knew if she got a bit of beginner's luck and started winning, she'd probably never stop. Tina had an addictive personality. It was part of her genetic make-up. All through her early and mid-teens she'd resisted the peer pressure to start smoking, then at seventeen she'd tried her first cigarette at a party and she'd been putting away twenty a day ever since, with every attempt to stop ending in rapid failure.

She wondered if Phelan was the same. Because he definitely had a gambling problem, and the Lively Lounge Club and Casino was where he sank the lion's share of the money he spent on his betting. And he spent a lot. Tina's team had got hold of copies of the previous year's statements for the five credit cards and one debit card held in his name, and during that period his outgoings amounted to a grand total of £87,288.36 – and this from a man with no actual income that they could find, other than a £1,500-a-month standing order paid into his personal bank account from Andrea's own account, which was held at a separate bank. There'd been a number of further payments into his account over the course of the year, more than twenty-five grand's worth in all, but they were sporadic which meant they almost certainly represented winnings. Even with his wife's £160,000-a-year salary it was an unsustainable amount, and already Phelan's credit limit was maxed out on every one of the credit cards, while he was currently overdrawn at the bank by more than six thousand.

It wasn't that someone getting himself into this situation was all that uncommon. As Big Barry had pointed out earlier that morning, people got themselves into serious debt the whole time. What was interesting about Pat Phelan's finances from a SOCA point of view was that his spending had tailed off dramatically in the last two months, by more than 90 per cent, and in the same period there'd been no deposits of winnings in his bank account. Either he'd turned over a new leaf or, in Tina's opinion far more likely, he was funding his habit from a different source. Since the financial statements all pointed to the Lively Lounge as the venue of choice for his gambling, Tina had decided that it was as good a place as any to start digging into Phelan's background. She could have left it to one of the more junior members of the team but, like a lot of detectives, she liked to get out and about; and if she was entirely honest with herself, she wasn't much of a delegator, preferring to rely on her own ability to get things done.

The needs of the compulsive gambler tend to be of the twenty-four-hour variety, and the club was open. Tina went through the tinted double doors and into the darkened lobby. A blonde girl was at the reception desk talking to an older woman with hair extensions and far too much make-up. The girl smiled politely as Tina approached, wishing her a good afternoon in a Polish accent. Her colleague, meanwhile, said nothing but gave her a more suspicious look, clocking immediately that she was police, even though Tina wasn't wearing a uniform and always made a conscious effort never to give off that aura. Some people simply have a nose for spotting coppers, and they're usually the ones who have the most to fear from them.

Tina smiled at the girl. 'Good afternoon, my name's Tina Boyd from the Serious and Organized Crime Agency.' She held up her warrant card. 'I'd like to speak to the owner, please.'

'I'll deal with this, Barbara,' said the older woman in a deep voice that was midway between a bear and Demi Moore. 'The owners aren't here.

They're not based in this country.' Her expression seemed to add, so what the hell are you going to do about that? 'Is there anything I can help with?'

'That depends. Are you the most senior person in the building at the moment?'

There was a moment's hesitation that told Tina the answer was no.

'Well, Mr McMahon's here, but-'

'And what's his position?'

'He's the manager, but I think he's-'

'Well, I'll see him then, thank you.'

'He's busy, Miss whatever-your-name-was,' the woman growled.

Tina wasn't deterred. 'That makes two of us. Can you take me to him, please?'

'I'll call up and see if he's available.'

She picked up a phone behind the desk, scowling at Tina, who stared back at her impassively, amazed why some people always had to put up a token resistance to the police before they acquiesced, even though the end result was inevitable.

The woman hung up. 'OK, he can see you now.'

Tina followed her through the main gambling area, a big, windowless place with all the charm of an aircraft hangar. Only a handful of the gaming tables were in use, the clientele mainly quiet Chinese men wearing inscrutable expressions as they placed their bets. None of them looked up as Tina and her guide passed by in silence.

Mr McMahon's office was at the far end of the building, up a flight of stairs and along a short corridor. The woman knocked on his door and moved out of the way for Tina to go in, giving her a last glare of defiance as she did so.

'The Serious and Organized Crime Agency,' said the man standing behind the desk as Tina shut the door behind her. 'I've not had any dealings with them. Malcolm McMahon,' he said, putting out a hand. 'Pleased to meet you, Miss…'

'Boyd. Tina Boyd.'

They shook hands, and Tina took the seat on her side of the desk.

Malcolm McMahon was a big man who looked like he enjoyed a drink. He was good-looking in a brutish sort of way, with slicked-back grey hair fashioned into a widow's peak as sharp as an arrowhead, and a straight one-inch scar edging away from his top lip. He was dressed in a badly ironed shirt and unfashionable striped tie, while his casino clothes – black suit and dress shirt – were hanging up on one wall, next to a bank of eight small screens that showed the gaming area from various angles.

'I hear you SOCA people aren't even police any more,' he said with a smile. 'You're special agents or something. So, what do I call you?'

'Miss Boyd'll do fine.'

He nodded slowly, accepting this. 'Well, Miss Boyd, we run a tight ship here, and we don't tolerate anything illegal, so I don't know how we came to the attention of SOCA. Do you mind if I check your ID again? Just to make sure you are who you say you are. It's amazing how many charlatans there are these days.'

'Sure.'

Tina produced the warrant card from the back pocket of her jeans and handed it to him, noticing the nicotine stains on his thick, stubby fingers as he took it. He examined it carefully before thanking her and handing it back.

'It's about one of your customers.'

'I don't like talking about our customers, Miss Boyd. They value their privacy, and so do we.'

'This is a very serious case, Mr McMahon. If you want me to get official and bring officers down here to interview all your staff, I can. But I'm also prepared to talk off the record, and I can guarantee that anything you tell me will be treated in the strictest confidence.'

'So, you want me to grass up one of my paying punters?' he asked evenly.

Now it was her turn to smile. 'No, I want you to help him. His name's Patrick Phelan, and I know he spends a lot of money in your establishment, and has done so for a long time.' McMahon didn't say anything, so she continued. 'Mr Phelan's gone missing, and we're extremely concerned about his welfare.'