Narrator: In 1876, a young, ambitious medical student named Sigmund Freud was sent to a research station in Trieste with a singular, frustrating task: to find the testicles of an eel. For weeks, he dissected over four hundred of the slippery, serpentine fish, searching for the male reproductive organs that had eluded scientists for centuries. He peered through his microscope, his frustration mounting with each failed attempt. In the end, he had to admit defeat. The eel had kept its secret. This creature, so common it was sold in every market, remained a profound biological puzzle, a question mark that even a mind like Freud's could not straighten into an answer.

This enduring mystery is the heart of Patrik Svensson’s The Book of Eels. It’s a work that masterfully blends natural history, scientific discovery, and poignant personal memoir to explore why this enigmatic creature has captivated philosophers, scientists, and fishermen for millennia. The book reveals that our long-standing obsession with the eel is ultimately a reflection of our own struggle with the great, unanswered questions of life itself.

Narrator: For most of human history, the eel existed as a creature of pure mystery, seemingly defying the basic laws of nature. The question of its origin was so profound it became known simply as "the eel question." The great philosopher Aristotle, a man who built his understanding of the world on empirical observation, was completely stumped. After observing ponds that would dry up and then, after a rain, suddenly teem with eels, he came to a logical, yet entirely wrong, conclusion. He declared that eels were not born from other eels but were generated spontaneously from the "entrails of the wet earth." For two thousand years, this idea—that eels were born of mud—was the accepted truth.

This mystery didn't just perplex the ancients. It continued to haunt the modern scientific age. The story of Sigmund Freud’s youthful failure in Trieste is a perfect example. Before he turned his attention to the hidden depths of the human psyche, he tried to plumb the biological depths of the eel. His inability to find its reproductive organs was more than just a scientific setback; it was an early lesson in the elusiveness of truth. The eel’s sexuality was hidden, repressed, and stubbornly resistant to being brought into the light—a theme that would, perhaps not coincidentally, echo throughout his later psychoanalytic work. The eel proved that some truths are not easily dissected on a lab table, establishing it as a creature that represents the limits of human knowledge.

Narrator: For centuries, the eel question remained unsolved. Scientists knew that young, transparent "glass eels" arrived on European coasts from the sea, but no one knew where they came from. The answer would come from the obsessive, two-decade-long quest of a Danish marine biologist named Johannes Schmidt. Starting in the early 1900s, Schmidt embarked on a series of expeditions across the Atlantic. His method was simple in concept but monumental in execution. He reasoned that if he could find the smallest eel larvae, he would find their birthplace.

On ship after ship, Schmidt and his crew trawled the ocean, collecting and meticulously measuring the tiny, transparent, willow-leaf-shaped larvae. He discovered a clear pattern: the farther west he sailed into the Atlantic, the smaller the larvae became. His search was interrupted by World War I, but he resumed his work afterward, finally zeroing in on a strange, calm, seaweed-choked region of the ocean. It was the Sargasso Sea. Here, he found the smallest larvae ever recorded, some just a third of an inch long. He had found the eel’s cradle. In 1923, he published his findings, declaring the mystery solved.

And yet, a crucial part of the mystery remains. To this day, no one has ever witnessed an adult eel in the Sargasso Sea. No one has seen them mate or lay their eggs. Schmidt’s discovery, as groundbreaking as it was, was based on inference. The eel’s final, most intimate act remains a secret, a private ritual performed in the deep, dark waters, far from human eyes.

Narrator: Beyond the scientific mystery, the eel holds a deep, personal significance for the author, Patrik Svensson. For him, the eel is inextricably linked to his father. The book weaves a tender memoir of their relationship, a bond forged not in conversation but in the quiet, shared ritual of fishing for eels in the stream near his childhood home. His father, a hardworking road paver, was a man of few words, but in the act of baiting hooks, setting lines, and waiting in the gathering dusk, a profound connection was formed.

Svensson recounts how these fishing trips became a tradition, a world unto themselves. In one memorable story, they cross the stream in an old wooden boat to fish illegally on the other side, which was owned by a town fishing club. Hiding in the grass as a train rumbles past, the shared risk and quiet conspiracy create a powerful, unspoken bond. The fishing wasn't just about catching eels; it was about creating a shared history, a legacy passed from father to son. It was in these silent moments that the most important things were communicated. The eel became the medium for a love that was felt rather than spoken, a creature that connected them to each other and to the rhythms of the natural world.

Narrator: The eel evokes a powerful and often unsettling emotional response. It’s not just its snake-like appearance; it’s something deeper. The eel embodies what Freud termed the unheimlich, or the uncanny—the feeling of unease that arises when something is both familiar and strangely alien at the same time. An eel is a fish, but it can also travel over land. It lives in quiet streams but is born in a mythical sea. This ambiguity makes it a potent symbol in literature and art, often representing the darker, repressed aspects of life.

Nowhere is this more vivid than in Günter Grass’s novel The Tin Drum. In a horrifying scene, a fisherman pulls a severed horse's head from the water, and a writhing mass of eels pours from its eyes, nose, and mouth. The sight is so revolting it drives one character to a self-destructive binge of eating eels, which ultimately leads to her death. Here, the eel is a symbol of death, decay, and a nauseating life that springs from putrefaction. It represents a truth so ugly it can destroy you. This power to disturb and fascinate is central to the eel's identity. It’s a creature that forces us to confront things we might rather leave hidden in the depths.

Narrator: The final, and perhaps most urgent, part of the eel’s story is its catastrophic decline. The European eel is now critically endangered. Since the 1980s, the population of glass eels arriving in Europe has plummeted by over 90 percent. The causes are numerous, but they all point back to a single culprit: humanity. Pollution from industrial toxins and agricultural runoff poisons their waters. Hydroelectric dams and other physical barriers block their ancient migration routes. Overfishing has decimated their numbers. And now, climate change is altering the ocean currents that carry their larvae from the Sargasso Sea.

The eel’s plight is not an isolated tragedy. It’s a story that echoes that of the dodo and Steller's sea cow—species driven to extinction by human activity. The eel is a bellwether, a living indicator of the health of our planet’s aquatic ecosystems. Its slow disappearance is a quiet alarm bell, warning us of a much larger crisis. The book frames the eel’s struggle as part of the sixth mass extinction, the first one in Earth’s history caused by a single species. The fight to save the eel is therefore a fight to save a piece of ourselves, a test of whether we can correct the destructive course we have set.

Narrator: Ultimately, The Book of Eels reveals that the eel is more than just a fish; it is a living symbol of the unknown. The "eel question" is not just about a single species' life cycle. It’s a metaphor for the fundamental, unanswerable questions we all face about our own origins, our purpose, and our final destination. The eel’s journey from a distant, unseen birthplace to a life in our local streams, and its final, mysterious return to the sea to die, mirrors our own life’s journey into and out of the world.

The book leaves us with a profound and challenging paradox. To save the eel from extinction, we must intensify our efforts to study it, to track its journey, and to unravel its secrets. Yet in doing so, we risk destroying the very mystery that makes the eel so compelling. The ultimate question, then, is not just whether we can save the eel, but whether we can learn to cherish and protect a creature—and a world—that we may never fully understand.