Suddenly, one of Santiago’s lines dips on its pole. Quietly, he ships his oars and removes the line from the pole and into his hands so the fish won’t notice the tension. The line jerks repeatedly as a marlin, far below, nibbles on sardines. The old man hopes and prays that the fish—which he assumes must be big if it is so far out at this time of year—will swallow the tuna head that hides the hook.

A hard pull yanks the line; Santiago lets it unspool, hundreds of feet of it, as the big fish takes off at high speed; he connects extra spools of line to the one unreeling between his fingers. Suddenly he grips the line tightly and begins to pull it in until he can’t anymore. He holds on, and the boat begins to move northwest, pulled by the marlin.

Four hours later, Santiago still grips the line, bracing it against his back, as the fish drags the boat onward. Santiago manages to take a drink one-handedly from his water bottle. More hours pass; the fish keeps swimming, the sun sets, and night falls. The old man wraps a sack around his shoulders for warmth.