"There are letters here for you, sir."
The mate of the vessel called out at once, "Send them off in the shore-boat; we'll lay-to."
No time was to be lost, for if the Smeaton should get involved in the fog it might be very difficult to find her; so Ruby at once ran for the letters, and, hailing the shore-boat which lay quite close at hand, jumped into it and pushed off.
They boarded the Smeaton without difficulty and delivered the letters.
Instead of returning to the beacon, however, Ruby was ordered to hold himself in readiness to go to Arbroath in the shore-boat with a letter from Mr. Stevenson to the superintendent of the workyard.
"You can go up and see your friends in the town, if you choose," said the engineer, "but be sure to return by tomorrow's forenoon tide. We cannot dispense with your services longer than a few hours, my lad, so I shall expect you to make no unnecessary delay."
"You may depend upon me, sir," said Ruby, touching his cap, as he turned away and leaped into the boat.
A light breeze was now blowing, so that the sails could be used. In less than a quarter of an hour sloop and beacon were lost in the fog, and Ruby steered for the harbour of Arbroath, overjoyed at this unexpected and happy turn of events, which gave him an opportunity of solving the mystery of the letters, and of once more seeing the sweet face of Minnie Gray.
But an incident occurred which delayed these desirable ends, and utterly changed the current of Ruby's fortunes for a time.