The story begins in 1518, Diego de Godoy, a young gentleman of Seville, embarks on a quest. He joins Cortes and his Conquistadors to win fame, fortune, and the hand in marriage of Isabella de Quintallina, a spoiled Spanish beauty who demands that he return from the New World bearing a gift for her that no man or woman has ever received before.
In America, Diego ponders many wonderful, beautiful, and special things--gold and gems, exquisite ornaments fashioned from these by the natives, and exquisitely embroidered garments, spices, animals, tobacco, fruits and vegetables--but what is unique enough to be worthy of the petulant beauty waiting for him back home? Then, one night at a banquet hosted by the Great Chief Montezuma, he finds the answer to that question when he is served a drink like no other he has ever tasted before--a bittersweet dark brown concoction that soothes like a drug and leaves him craving more. The natives call it chocolatl, it is made from the precious cacoa beans that the natives use as currency.
Diego is instantly smitten with the Aztec woman who serves him this delicious and intriguing beverage. He calls her Ignacia as her true name, Quiauhxochitl, is unpronouncable, and as memories of Isabella grow dim, he seeks every opportunity to be in her company and learn more about chocolatl. The two fall in love, but despair in the grim face of reality; they come from two different worlds, and Deigo's people have come to conquer and bring death and destruction to Ignacia's people and the land that she loves. But in Ignacia's heart hope springs eternal, and she is prepared to gamble with fate; unbeknownst to Diego she slips the magical elixir of life into his chocolatl and gives him immortality, hoping that somehow, someway, someday, in the centuries to come, their love will survive and they will find each other again.
The lovers part amidst the bloody and violent chaos of the Mexican Conquest. Diego returns to Spain and, despite his yearning for Ignacia, tries to rekindle his love for Isabella. After two years apart, the couple find they have little liking for, and even less to say to, each other. But true to his word, Diego comes bearing a unique gift--a vase filled with the precious cacoa beans pilfered from Montezuma's treasury. But he has made a great blunder--the beans are fakes, fashioned from bits of dried clay, seized by Montezuma's men as counterfeit currency.
Disgraced and a laughingstock, Diego departs Seville and returns to Mexico, determined to start a new life with Ignacia, only to discover amidst the blackened and charred ruins of the once great city what he believes is his beloved's grave. Consumed with grief and longing, he is slow to realize his immortality as the years creep by. With his loyal greyhound Pedro, who licked the dregs of the chocolatl containing the elixir, Diego becomes a solitary and discontent wanderer, fated to traverse the centuries lonely and loveless; touching others' lives temporarily but never truly sharing them as his immortality condemns him to always move on. He cannot settle down and grow old with someone, he cannot bear to watch as they age, sicken, and die while he remains alive, aging only minimally as the decades pass.
As the years slowly unfold, his destiny entwines with chocolate; it becomes his passion, his one true and vital link to Ignacia. He causes a furor that leads to religious discord and murder in a sleepy little Mexican town when he introduces his innovative recipe for hot chocolate. Imprisoned in the Bastille as a madman, he makes dark chocolate raspberry cremes with the Marquis de Sade, and helps overthrow the Bastille and perfect the pain au chocolat as the fires of the French Revolution ignite. In Vienna, he turns a ruined cake into the famous Sacher Torte, and ends up on the couch of Sigmund Freud when the burden of immortality weighs too heavily on his soul. He makes a fresh start in England under the guidance of kindly, fatherly Quaker philanthropist Joseph Fry as they work together to perfect the chocolate bar at his factory in Bristol. And he discusses the intricacies of chocolate mousse with Gertrude Stein and Alice B. Toklas aboard The Mauritania as he sails to start yet another new life in America, in Hershey, Pennsylvania, after a fateful encounter with Milton S. Hershey at the greyhound races results in the birth of Hershey Kisses. Until his long quest for love, redemption, and peace of mind brings him full circle and back to Mexico.
Surprisingly, given the time span it covers, "The Discovery of Chocolate" is, at only 264 pages, short enough to devour in one or two sittings. It's a chocolate bar of a book, easily and quickly finished, but, depending on the reader's appetite and enjoyment of it, it may leave them wanting more.