"Hear that, sir!" Billy exclaimed.
They listened.
"Breaking up fast!" said the Doctor.
Again there was a splitting crash. Another great fragment of the ice had broken away.
"Come on!" cried Billy, in alarm.
At first prolonged intervals of moonlight had occurred. Masses of cloud had gone driving across a pale and faintly starlit sky. A new proportion was disclosed. Now the stars were brilliant in occasional patches of deep sky. A glimpse of the moon was rare. From the northeast the ominous bank of black cloud had risen nearly overhead. It would eventually curtain both stars and moon and make a thick black night of it.
A man would surely lose his life on the ice in thick weather—on one or other of the reaches of new ice. And thereabouts the areas of young ice were wider. They were also more tender. Thin ice is a proverb of peril and daring. To tiptoe across the yielding film of these dimly visible stretches was instantly and dreadfully dangerous. It was horrifying. A man took his life in his hand every time he left a pan.
Doctor Luke was not insensitive. Neither was Billy Topsail. They began to sweat—not with labour, but with fear. When the ice bent under them, they gasped and held their breath. They were in livid terror of being dropped through into the sea. They were afraid to proceed—they dared not stand still; and they came each time to the solid refuge of a pan with breath drawn, teeth set, faces contorted, hands clenched—a shiver in the small of the back. This was more exhausting than the labour of the folded floe. Upon every occasion it was like escaping an abyss.
To achieve safety once, however, was not to win a final relief—it was merely to confront, in the same circumstances, a precisely similar peril. Neither Doctor Luke nor Billy Topsail was physically exhausted. Every muscle that they had was warm and alert. Yet they were weak. A repetition of suspense had unnerved them. A full hour of this and sometimes they chattered and shook in a nervous chill.