‘Come, come, my young friend, you’re talking at random. To begin with, although I have taken my degree, I do not practise medicine. Strictly speaking, I am not a doctor—not a doctor of the body, that is.’

Jack looked at him keenly.

‘Of the mind?’

‘Yes, in a sense, but more truly I call myself a doctor of the soul.’

‘Oh!’

‘I perceive the disparagement in your tone, and yet we must use some word to denote the active principle which can be separated and exist independently of its fleshy home, the body. You’ve got to come to terms with the soul, you know, young man, it isn’t just a religious term invented by clergymen. But we’ll call it the mind, or the subconscious self, or any term that suits you better. You took offence at my tone just now, but I can assure you that it really did strike me as very curious that such a well-balanced and perfectly normal young man as yourself should suffer from the delusion that he was going out of his mind.’

‘I’m out of my mind all right. Absolutely barmy.’

‘You will forgive me for saying so, but I don’t believe it.’

‘I suffer from delusions.’

‘After dinner?’

‘No, in the morning.’

‘Can’t be done,’ said the doctor, relighting his pipe which had gone out.

‘I tell you I hear things that no one else hears.’

‘One man in a thousand can see the moons of Jupiter. Because the other nine hundred and ninety nine can’t see them there’s no reason to doubt that the moons of Jupiter exist, and certainly no reason for calling the thousandth man a lunatic.’

‘The moons of Jupiter are a proved scientific fact.’

‘It’s quite possible that the delusions of today may be the proved scientific facts of tomorrow.’

In spite of himself, Lavington’s matter-of-fact manner was having its effect upon Jack. He felt immeasurably soothed and cheered. The doctor looked at him attentively for a minute or two and then nodded.

‘That’s better,’ he said. ‘The trouble with you young fellows is that you’re so cocksure nothing can exist outside your own philosophy that you get the wind up when something occurs to jolt you out of that opinion. Let’s hear your grounds for believing that you’re going mad, and we’ll decide whether or not to lock you up afterwards.’

As faithfully as he could, Jack narrated the whole series of occurrences.

‘But what I can’t understand,’ he ended, ‘is why this morning it should come at half past seven—five minutes late.’

Lavington thought for a minute or two. Then—

‘What’s the time now by your watch?’ he asked.

‘Quarter to eight,’ replied Jack, consulting it.

‘That’s simple enough, then. Mine says twenty to eight. Your watch is five minutes fast. That’s a very interesting and important point—to me. In fact, it’s invaluable.’

‘In what way?’

Jack was beginning to get interested.

‘Well, the obvious explanation is that on the first morning you did hear some such cry—may have been a joke, may not. On the following mornings, you suggestioned yourself to hear it at exactly the same time.’