‘Dr Raven. Always a pleasure. To what do I owe this unannounced visit?’

He spoke flatly but Raven detected a wariness.

‘Yes, apologies for the unheralded nature of my call. Normally I prefer to be conveyed to you against my will, but I happened to be passing and I saw Mr James Quinton leaving here with the look of a man not keen that anyone should know his business. I am curious as to the nature of your relationship with him.’

‘That’s what we respectable men of business refer to as confidential,’ Flint stated with barely contained aggression, a warning to back off. ‘A matter between me and him.’

Raven did not flinch from his gaze.

‘I might suggest it was a matter between you, him and some stolen stock certificates.’

Flint reached for the pistol, but before he had it cocked, Raven had his knife resting on the money-lender’s throat.

Their eyes were locked upon each other, Raven pressing gently with the blade, Flint’s weapon an inch from Raven’s belly.

‘This pistol has a Forsyth percussion lock,’ Flint stated. ‘It uses fulminate of mercury instead of priming powder. So there is no delay between my pulling this trigger and the charge firing. You saw what a lesser weapon did to poor Alec.’

‘And this is a Liston knife. The man could take a leg off through the thighbone with such a blade in twenty-eight seconds. Imagine what it would do to the soft flesh of your throat should my wrist twitch in response to you pulling that trigger.’

Flint pointed the gun away. He backed off a step, putting the pistol back down on the desk.

Raven lowered the knife, though he kept it in his hand.

He knew there could be no winning such a stand-off. The same applied to the discussion he wished to have. With a man such as Flint, you had to make him believe he had the upper hand, or you would remain in stalemate.

‘We had an agreement. I honoured my side of the bargain in supplying you with chloroform. I am asking you to reciprocate by supplying information. What is Quinton doing for you?’

Flint laughed. ‘Primarily he is doing precisely what he does for your Dr Simpson. He is keeping my books.’

‘And what else?’

Flint glanced at the strongbox. They both understood that Raven wouldn’t be asking this question if he didn’t already know the answer. This wasn’t the part he was most interested in.

‘His skills as a calligrapher and his knowledge of the stock market are also proving useful.’

‘Why did he need to borrow money from the likes of you?’

Flint gave an amused shrug. ‘I never ask,’ he said. ‘But I always collect. And sometimes I take payment in kind, as you well know. Services rendered.’

‘How much is his debt?’