Early next morning, 20 May, seeing Husvik Harbour below them, the party knew that they were on the right path. At seven o'clock in the morning, they heard a steam whistle sound from Stromness, "the first sound created by an outside human agency that had come to our ears since we left Stromness Bay in December 1914".[90] After a difficult descent, which involved passage down through a freezing waterfall, they at last reached safety.[91] Shackleton wrote afterwards: "I have no doubt that Providence guided us ... I know that during that long and racking march of 36 hours over the unnamed mountains and glaciers it seemed to me often that we were four, not three".[92] This image of a fourth traveller was echoed in the accounts of Worsley and Crean and later influenced T. S. Eliot in the writing of his poem The Waste Land.[93]