Luis Gelán, a world-famous boxer known for his rapid and glorious career, nicknamed the Bull of the Pampas, who left boxing for love of his wife Isabel, lives with them at the Los Sauces ranch. Meanwhile, Bob Jackson, his former sparring partner, also retired, awaits the opportunity when Gelán returns to the ring and needs him. It is then that his sick son needs medication, and he decides to return to boxing.