‘Listen, Nella,’ said the latter, drawing his daughter to him in the profound gloom of the cellar. ‘We fancy that Jules may be trying to tamper with a certain bottle of wine—a bottle which might possibly be drunk by Prince Eugen. Now do you think that the man you saw might have been Jules?’

‘I hadn’t previously thought of him as being Jules, but immediately you mentioned the name I somehow knew that he was. Yes, I am sure it was Jules.’

‘Well, just hear what I have to say. There is no time to lose. If he is coming at all he will be here very soon—and you can help.’ Racksole explained what he thought Jules’ tactics might be. He proposed that if the man returned he should not be interfered with, but merely watched from the other side of the glass door.

‘You want, as it were, to catch Mr Jules alive?’ said Babylon, who seemed rather taken aback at this novel method of dealing with criminals. ‘Surely,’ he added, ‘it would be simpler and easier to inform the police of your suspicion, and to leave everything to them.’

‘My dear fellow,’ said Racksole, ‘we have already gone much too far without the police to make it advisable for us to call them in at this somewhat advanced stage of the proceedings. Besides, if you must know it, I have a particular desire to capture the scoundrel myself. I will leave you and Nella here, since Nella insists on seeing everything, and I will arrange things so that once he has entered the cellar Jules will not get out of it again—at any rate through the grating. You had better place yourselves on the other side of the glass door, in the big cellar; you will be in a position to observe from there, I will skip off at once. All you have to do is to take note of what the fellow does. If he has any accomplices within the hotel we shall probably be able by that means to discover who the accomplice is.’

Lighting a match and shading it with his hands, Racksole showed them both out of the little cellar. ‘Now if you lock this glass door on the outside he can’t escape this way: the panes of glass are too small, and the woodwork too stout. So, if he comes into the trap, you two will have the pleasure of actually seeing him frantically writhe therein, without any personal danger; but perhaps you’d better not show yourselves.’

In another moment Felix Babylon and Nella were left to themselves in the darkness of the cellar, listening to the receding footfalls of Theodore Racksole. But the sound of these footfalls had not died away before another sound greeted their ears—the grating of the small cellar was being removed.

‘I hope your father will be in time,’ whispered Felix

‘Hush!’ the girl warned him, and they stooped side by side in tense silence.

A man cautiously but very neatly wormed his body through the aperture of the grating. The watchers could only see his form indistinctly in the darkness.