"Madam, it is more than twenty-four hours since we left the fort. We now know the thickness of the ice-wall, and as we promised not to be away longer than forty-eight hours, I think it is time to retrace our steps."
Mrs Barnett saw the justice of the Lieutenant's remark. They had ascertained that the barrier of ice was of moderate thickness, that it would melt away quickly enough to allow of the passage of Mac-Nab's boat after the thaw, and it would therefore be well to hasten back lest a snow-storm or change in the weather of any kind should render return through the winding valley difficult.
The party breakfasted and set out on the return journey about one o'clock P.M.
The night was passed as before in an ice-cavern, and the route resumed at eight o'clock the next morning, March 9th.
The travellers now turned their backs upon the sun, as they were making for the west, but the weather was fine, and the orb of day, already high in the heavens, flung some of its rays across the valley and lit up the glittering ice-walls on either side.
Mrs Barnett and Kalumah were a little behind the rest of the party chatting together, and looking about them as they wound through the narrow passages pointed out by Marbre and Sabine. They expected to get out of the valley quickly, and be back at the fort before sunset, as they had only two or three miles of the island to cross after leaving the ice. This would be a few hours after the time fixed, but not long enough to cause any serious anxiety to their friends at home.
They made their calculation without allowing for an incident which no human perspicacity could possibly have foreseen.
It was about ten o'clock when Marbre and Sabine, who were some twenty paces in advance of the rest, suddenly stopped and appeared to be debating some point. When the others came up, Sabine was holding out his compass to Marbre, who was staring at it with an expression of the utmost astonishment.
"What an extraordinary thing!" he exclaimed, and added, turning to the Lieutenant-
"Will you tell me, sir, the position of the island with regard to the ice-wall, is it on the east or west?"