An aging Cuban fisherman engages in a grueling, multi-day battle with a giant marlin in the Gulf Stream, testing the limits of his physical endurance and resolve. Santiago, a veteran fisherman who has gone eighty-four days without a catch, ventures far into the Gulf Stream to reclaim his reputation. He hooks a massive marlin that pulls his small skiff into the deep, forcing a solitary confrontation between man and nature. The narrative framework is third-person limited, focusing intensely on Santiago’s internal monologue and his sensory experience of the sea. His objective is to secure the fish, but he faces the dual opposition of the creature's immense strength and the encroaching threat of sharks that seek to scavenge his prize.

Discussion often centers on the economy of Hemingway’s prose and its effectiveness in conveying complex themes through simple action. Readers frequently highlight the stark atmosphere of the sea, which serves as both a setting and a character in its own right. Critics often analyze the novella as a meditation on aging, pride, and the nature of victory in defeat. The balance between the visceral, technical details of the hunt and the philosophical weight of Santiago’s reflections remains a primary point of interest for scholars and casual readers alike.