'Perhaps it will be. I regret to tear you from your fireside, Alb, but I wish to consult you on a matter affecting the governor.'

'Go ahead, then,' said Albert. 'There's been enough talk about the governor to-day downstairs, I should hope.'

'You mean in reference to Mrs. Tudor's reappearance?'

'Yes.' Albert imitated Simon's carefully enunciated periods. 'I do mean in reference to Mrs. Tudor's reappearance. By the way, what the deuce are you burning all these lights for?'

'I was examining this photograph,' said Simon, handing to his brother a rather large unmounted silver-print photograph which had lain on his knees.

'What of it?' Albert asked, glancing at it. 'Medical and Pharmaceutical Department, isn't it? Not bad.'

'We're having a new series of full-plate photographs done for the next edition of the General Catalogue,' said Simon, 'and this is one of them.

It contains forty-five figures. It was taken yesterday morning by that Curgenven flashlight process that we're running. Look at it. Don't you see anything?'

'Nothing special,' Albert admitted.

Simon rose and came towards the piano.

'Let me show you,' he said superiorly. 'You see the cash-desk to the left. There's a lady just leaving the cash-desk. And just behind her there's an oldish man. You can't see all of his face because of her hat.

He's holding his bill in his hand--you can see the corner of it--and he's got some sort of a parcel under his arm. See?'

'Yes, Mr. Lecoq.'

'Well, doesn't he remind you of somebody?'

'He's rather like old Ravengar, perhaps,' said Albert dubiously.

'You've hit it!' Simon almost shouted. 'It is Ravengar.'

'This man's got no beard.'

'That comes well from a detective, that does!' said Simon scornfully.

'It needn't have cost him more than threepence to have his beard shaved off, need it?'

'And seeing that this photograph was taken yesterday morning, and Ravengar fell off a steamer into the Channel more than a week ago!'

'But did he fall off a steamer more than a week ago?'

'He was noticed on board the steamer before she started, and he wasn't on board when she arrived.'

'Couldn't he have walked on to the steamer with his luggage, and then walked off again and let her start without him?'

'But why?'

'Suppose he wanted to pretend to be dead?'

'Why should he want to pretend to be dead?' Albert defended his position.

Simon, entirely forgetful of that dignity which usually he was at such pains to preserve, sprang on to the piano alongside Albert.

'I'll tell you another thing,' said he. 'When I came in with the governor's tea this morning he was just dozing and half-dreaming like--he'd had a very bad night--and I heard him say, "So they think you are at the bottom of the Channel, Louis? I wish you were!" What do you think of that, my son?'

'Then the governor must know Ravengar didn't commit suicide in the Channel? The governor never said a word to me!'

'You don't imagine the governor tells you everything, do you?' said Simon cruelly.

'Have you shown him the photo?' Albert asked.

'No,' said Simon, with a certain bluntness.

'Why not?'

'Well, for one thing, I've had no chance, and for another I wanted to find out something more first. I'd just like the governor to see that I'm not an absolute idiot.... Though I should have thought he might have found that out before now.'

'He doesn't think you're an absolute idiot,' said Albert.

'He acts as if he did,' said Simon. The Paris trip still rankled.

A pause followed.

'Another thing,' Albert recommenced. 'Even supposing Ravengar's alive, it's not very likely he'd venture here, of all places.'

'Why not?' Simon argued. 'Scarcely anybody knows Ravengar by sight. He's famous for keeping himself to himself. He's one of the least known celebrities in London. He'd be safe from recognition almost anywhere.

Moreover, supposing he wanted to buy something peculiar?'

'He might,' Albert admitted. 'But don't forget this is all theory. I suppose you've been making your own inquiries in the Medical Department?'

'Yes,' said Simon rather apologetically. 'But I couldn't find anyone among the staff who remembers serving such a man, or even seeing him.

He may have had an accomplice, you know, on the staff. What makes it more awkward is that there were two photographs taken, one about eleven, and another about half-past, and the photographer got the plates mixed up, and doesn't know whether this one is the first or the second. You see, the clock doesn't show in the picture; otherwise, we might have pieced things together.'

'Pity!' Albert murmured.

'However,' said Simon, with an obvious intention to be dramatic, 'I thought of Lecoq, and I hit on something. You see the lady just leaving the cash-desk with her receipt? Can you read the number of her receipt?'

Albert peered.

'No, I can't,' he said.

'Neither could I,' Simon agreed. 'But I've had that part of the photograph enlarged to-night.'

'The deuce you have!' Albert opened his eyes.

'Yes, the deuce I have! And here it is.'

Simon took a photographic print from his pocket, showing the lady's hand and part of the receipt, very blurred and faint, with some hieroglyphic figures mistily appearing.

'Looks like 6,706,' said Albert.

'It's either 6,706 or 6,766,' Simon concurred. 'Now, Ravengar's receipt must be numbered next to hers. Consequently, if we go and look at the counterfoils and duplicates--'