‘Scotland Yard, no less! I’d be happy to assist you, detective, but what can I offer that your redoubtable police force can’t?’

‘For starters, you might be able to advise me how to deal with a loan shark your grandpa wouldn’t have done business with.’

‘Will you be taking dinner, gentlemen?’ asked a stewardess, as she offered them both a menu.

‘Sure will, miss,’ said Larry.

‘Me too,’ said Ross.

‘OK,’ said Larry, once she’d taken their orders. ‘Walk me through your problem slowly, and don’t leave out any details, however mundane they might seem to you.’

Ross took his time telling Larry everything the police knew about Max Sleeman, his associates and the methods they used to make sure his customers repaid their debts punctually.

The stewardess had cleared away their trays and was serving coffee before Larry T. Holbrooke the Third offered an opinion.

‘Fascinating,’ said Larry, as he dropped three sugar lumps in his coffee. ‘With two words you revealed Sleeman’s Achilles heel, which you can now take advantage of.’

‘As long as I can identify those two words.’

Larry began to stir. ‘You have the bow, detective, all I can do is supply the arrows.’

‘Detectives rely on clues,’ Ross reminded him.

Larry took a sip of coffee, before drawing an arrow from his sheath. ‘When did Sleeman tell you he’d be collecting the first payment of six hundred pounds?’

‘On the first day of the month, without fail.’

‘“Without fail” are the two words you have to take advantage of. Because you now know the time and the place when his collector will appear.’

‘I can’t be certain of the time,’ said Ross.

‘You’ll be the first call he makes that morning,’ said Larry, as a steward topped up their coffee.

‘How can you be so sure?’

‘First payments are always the easiest to collect. It’s later, when the borrower gets deeper and deeper into debt and can’t pay up, even if he wants to, that the real trouble begins. I always give my customers a few days’ grace, but then I’m not just interested in a single transaction. That’s not possible for the Sleemans of this world, who deal in threats and deadlines. So you have to make sure that when his collector turns up on the first day of the month, you have the six hundred pounds ready to hand over. Then you’ll be in the driving seat.’

‘I know you’re going to tell me why,’ said Ross.

‘Don’t forget, he’ll be spending the rest of the day collecting money from less willing customers. You can be sure he’ll leave the most difficult one to last, and I have a feeling you’ll want to be present when that happens.’

‘How dumb of me,’ said Ross.

‘Not at all. I’ve been in the debt-collecting business for over thirty years, and during that time I’ve come across crooks every bit as ruthless as your Sleeman guy. You’ll be pleased to hear they usually end up dying alone with no one attending their funerals.’