As Merton sped on the motor next day to the nearest telegraph station, with Mr. Macrae’s sheaf of despatches, Dr. MacTavish found him a very dull companion.  He named the lochs and hills, Quinag, Suilvean, Ben Mor, he dwelt on the merits of the trout in the lochs; he showed the melancholy improvements of the old Duke; he spoke of duchesses and of crofters, of anglers and tourists; he pointed to the ruined castle of the man who sold the great Montrose—­or did not sell him.  Merton was irresponsive, trying to think.  What was this mystery?  Why did the wireless machine bring no response from its headquarters; or how could practical jokers have intruded into the secret chambers of Messrs. Gianesi and Giambresi?  These dreams or visions of his own on the night before Miss Macrae was taken—­were they wholly due to tobacco and the liver?

‘I thought I was awake,’ said Merton to himself, ’when I was only dreaming about the crimson blot on the ceiling.  Was I asleep when I saw the tartans go down the stairs?  I used to walk in my sleep as a boy.  It is very queer!’

‘Frae the top o’ Ben Mor,’ the doctor was saying, ’on a fine day, they tell me, with a glass you can pick up “The Seven Hunters."’

’Eh, what?  I beg your pardon, I am so confused by this wretched affair.  What did you say you can pick up?’

‘Just “The Seven Hunters,"’ said the doctor rather sulkily.

‘And what are “The Seven Hunters"?’

‘Just seven wee sma’ islandies ahint the Butt of Lewis.  The maps ca’ them the Flanan Islands.’

Merton’s heart gave a thump.  The first message from the Gianesi invention was dated ‘The Seven Hunters.’  Here was a clue.

‘Are the islands inhabited?’ asked Merton.

‘Just wi’ wild goats, and, maybe, fishers drying their fish.  And three men in a lighthouse on one of them,’ said the doctor.

They now rushed up to the hotel and telegraph office of Inchnadampf.  The doctor, after visiting the bar, went on in the motor to Lairg; it was to return for Merton, who had business enough on hand in sending the despatches.  He was thinking over ‘The Seven Hunters.’  It might be, probably was, a blind, or the kidnappers, having touched there, might have departed in any direction—­to Iceland, for what he knew.  But the name, ‘the Seven Hunters,’ was not likely to have been invented by a practical joker in London.  If not, the conspirators had really captured and kept to themselves Mr. Macrae’s line of wireless communications.  How could that have been done?  Merton bitterly regretted that his general information did not include electrical science.

However, he had first to send the despatches.  In one Mr. Macrae informed Gianesi and Giambresi of the condition of their instrument, and bade them send another at once with a skilled operator, and to look out for probable tamperers in their own establishment.  This despatch was in a cypher which before he got the new invention, and while he used the old wires, Mr. Macrae had arranged with the electricians.  The words of the despatch were, therefore, peculiar, and the Highland lass who operated, a girl of great beauty and modesty, at first declined to transmit the message.