Mr. Macrae all but embraced Merton.  ’Had I a son, I could have wished him to be like you,’ he said; ‘but my poor boy—­’ his voice broke.  Merton had not known before that the millionaire had lost a son.  He did understand, however, that the judicious Logan had given him the whole credit of the exploit, for reasons too obvious to Merton.

‘Don’t thank me,’ he was saying, when Logan interrupted: 

’Don’t you think, Mr. Macrae, you had better examine the message that has just come in?’

Mr. Macrae read, ’Glad they found the hair-pin, it will console the old boy.  Do not quite see how to communicate, if Gianesi, who, you say, has arrived, removes the machine.’

‘Look here,’ cried Merton, ’excuse my offering advice, but we ought, I think, to send for Donald Macdonald at once.  We must flash back a message to those brutes, so they may think they are still in communication with the traitor in our camp.  That beast on the floor could work it, of course, but he would only warn them; we can’t check him.  We must use Donald, and keep them thinking that they are sending news to the traitor.’

‘But, by Jove,’ said Logan, ’they have heard from him, whoever he is, since Bude came back, for they know about the finding of the hair-pin.  You,’ he said to the wretched captive, ‘have you been at this machine?’

The man, being gagged, only gasped.

‘There’s this, too,’ said Merton, ’the senders of the last message clearly think that Gianesi is against them.  If Gianesi removes the machine, they say—­’

Merton did not finish his sentence, he rushed out of the room.  Presently he hurried back.  ‘Mr. Macrae,’ he said, ’Blake’s door is locked.  I can’t waken him, and, if he were in his room, the noise we have made must have wakened him already.  Logan, ungag that creature!’

Logan removed the gag.

‘Who are you?’ he asked.

The captive was silent.

‘Mr. Macrae,’ said Merton, ’may I run and bring Donald and the other servants here?  Donald must work the machine at once, and we must break in Blake’s door, and, if he is off, we must rouse the country after him.’

Mr. Macrae seemed almost dazed, the rapid sequence of unusual circumstances being remote from his experience.  In spite of the blaze of electric light, the morning was beginning to steal into the room; the refreshments on the table looked oddly dissipated, there was a heavy stale smell of tobacco, and of whisky from a bottle that had been upset in the struggle.  Mr. Macrae opened a window and inhaled the fresh air from the Atlantic.

This revived him.  ‘I’ll ring the alarm bell,’ he said, and, putting a small key to an unnoticed keyhole in a panel, he opened a tiny door, thrust in his hand, and pressed a knob.  Instantly from the Castle tower came the thunderous knell of the alarm.  ’I had it put in in case of fire or burglars,’ explained the millionaire, adding automatically, ’every modern improvement.’