On a freezing Tuesday in March 2009, my alarm blared at 4:00 a.m. By 6:45, I stood shivering outside a housing project in the South Bronx with Lieutenant John Fitzpatrick and three junior officers, fresh-faced graduates of the Academy. The entire scene was gray—the potholed roads, the sooty snow, the late-winter sky—except the officers themselves, who provided the only glimmer of green. Rather than standard NYPD issue, they wore olive uniforms and trooper hats, à la Ranger Smith from The Yogi Bear Show. As they crunched across the unshoveled walkway, a passing teenage girl wisecracked, “Ain’t you supposed to be in the forest?”

Fitzpatrick, who had been patrolling the same beat since 1996, ignored her, keeping his eyes trained on one of the brick high-rises lined up like dominoes. As a cop (of sorts) from Brooklyn, descended from a clan of cops from Brooklyn, he looked the part, a towering man of forty-one with a crew cut and dimpled chin. Tucked under his arm was a file containing a photograph of the suspect he was after—someone he believed could be armed and dangerous.

Inside, the building’s lobby was dimly lit and gloomy. The elevator clattered open, and we crowded in, squeaking up to the eighth floor, where the officers’ boots echoed down the long hall before halting outside one apartment. Fitzpatrick pounded on the door. After half a minute passed and nothing happened, he raised his fist again, pounding harder and longer. A baby cried down the hall. At last, a male voice, gravelly with sleep, croaked, “Who is it?”

“State Environmental Police,” Fitzpatrick announced.

“Who?” said the voice, sounding genuinely confused.

The door cracked open to reveal a stocky young man with full-sleeve tattoos wearing flannel pajama bottoms, his eyes squinting against the light. His name was Jason Cruz. Asked if he knew what brought the officers to his door, he shook his head no and said, “I don’t at all.”

“We’re here,” Fitzpatrick enlightened him, “because of the alligator that you were offering to sell on Craigslist.”

•  •  • 

I WAS REPORTING a story about exotic pets for a science program on NPR, and it had taken me six months to get permission to join Fitzpatrick, a detective with the New York State Department of Environmental Conservation, on one of his busts. When I’d first called him the previous summer, I’d found him brimming with bizarre tales from an urban bestiary. During his time policing the city’s illegal wildlife trade, he had encountered everything from gorilla-hand ashtrays to twelve hundred turtles crammed into a swank Tribeca loft, their owner left with no room for a bed. There was the Harlem man who kept Ming the tiger and Al the alligator in the apartment where his mother was raising eight small children; the wealthy Brooklyn family who treated their African Diana monkey, one of the rarest primate species on earth, like a second daughter—even threatening to barricade their home if marshals tried to take her away; and the proprietor of a popular curio store in SoHo who landed in prison for selling not only a chimpanzee skeleton and walrus tusks but also human body parts. From time to time, a notorious dealer called Mr. Anything Man surfaced in his jalopy advertising exotic live animals, dead or alive.

Anything. It’s the theme of the city’s wildlife trade. Sure enough, when Fitzpatrick asked the pajama-clad Cruz how he came by the alligator he’d been trying to sell, Cruz shrugged and said, “This is the Bronx. You can get anything.”

Inside his apartment, which was small and tidy with a black leather couch, flatscreen TV, and mirrored photograph of the Manhattan skyline, a dog barked from the bathroom. Birds tweeted in the kitchen. Fitzpatrick walked over to a trio of tanks and inspected a leopard gecko in one and, in the other, a teaspoon-size baby Nile monitor—a yellow-striped lizard with a blue, forked tongue fond of devouring cats when full grown. The third tank was empty, except for a few inches of stagnant water, which Fitzpatrick leaned in to sniff suspiciously. “So where is the alligator now?” he asked.

“I gave it back,” Cruz said, claiming he’d bought the reptile from a stranger outside PetSmart on Pelham Parkway. Though it was only a foot long, his girlfriend had pointed out its likelihood of enlarging and insisted that it had to go for the sake of their two-year-old daughter. After this ultimatum, Cruz said he tried to unload the gator online, but Craigslist flagged the ad; so he returned it to the dealer who sold it to him in the first place. “He was a Puerto Rican dude,” he offered.

Fitzpatrick jotted this on a notepad. “Now it’s down to just a few million people in the Bronx,” he said drily.

I was as disappointed as Fitzpatrick to have narrowly missed the alligator. I’d been hoping for a scene like the time he taped up the snout of a three-foot-long caiman and drove it thrashing in his front passenger seat to the Bronx Zoo. What’s more, Cruz didn’t live up to Fitzpatrick’s billing of the typical alligator aficionado as an exemplar of machismo and aggression. Pet alligators were supposed to be particularly hot among gang members and drug dealers, but Cruz didn’t seem like either. Before his daughter was born, he used to keep pit bulls, as evidenced by black leather harnesses with metal studs hanging from the wall; but the dog barking in the bathroom turned out to be a poodle.

“You can really get in trouble over, like, an alligator?” Cruz asked Fitzpatrick, still bewildered by what was happening.

His pregnant girlfriend, who had emerged from the bedroom, yawning and looking unamused, added, “There’s a lot of people that sell alligators.”

“It’s a criminal offense,” Fitzpatrick told them, explaining that New York State prohibits the commercial sale of live crocodilians, while the city goes further, banning just about every exotic pet from scorpions to ferrets to polar bears. The Nile monitor was illegal too and would have to be seized. Cruz looked crestfallen as his girlfriend found an empty shoebox, into which he gingerly lifted the tiny lizard, wrapping it in a T-shirt to protect it from the cold.

“There’s not many animals you can keep here,” Fitzpatrick advised him, “except a dog, cat, goldfish, canary—”

“I got like twenty lovebirds!” Cruz exclaimed.

In the kitchen, Fitzpatrick inspected the stacked cages of small, green parrots with yellow chests and red beaks, deeming them permissible.

“If I didn’t have kids or nothing, I would’ve had cobras here, vipers, all types of stuff,” Cruz said wistfully, explaining that he had loved animals since he was a child, particularly after escaping the Bronx to visit his aunt in Florida where alligators sunned themselves in the backyard and took dips in the swimming pool. While waiting for the officers to write up a court summons, he called his mother and told her that he was going to be on Animal Planet.

“NPR,” I mouthed, then frowned, recalling how my producer had requested high drama—something along the lines of a wildebeest in Queens.

After hanging up, Cruz turned to me and grew philosophical: “You know what it is? You like animals, and you get tired of seeing the same animals over and over. You go to the pet store, and they have this and that—and you know everybody’s got it. So you try to get something different.”

“Honestly, that’s part of the problem,” Fitzpatrick said as he handed over the summons. “Then you get into endangered species.”

But Cruz, marveling at how easily he could acquire a fifteen-foot anaconda rumored to be for sale, didn’t seem to hear.

•  •  • 

MORE EXOTIC ANIMALS are believed to live in American homes than in American zoos. Yet the desire of someone like Cruz to keep an alligator in his living room defies classic theories of pet-keeping, which hold that humans keep pets for unconditional love, for example, or because a misdirected cute response (the scientific term) compels us to care for other species the way we do our own offspring. Alligators are neither affectionate nor cute, at least not in the sense of being cuddly and having large eyes, a round face, and an oversize head like a human infant or a pug dog. Rather, the appeal seems to lie in the opposite direction—the alligator’s ferocity, its wild and untamable nature.

In a way, what Cruz had assembled in his Bronx apartment could be seen as having a long historical precedent. It was a menagerie, a collection of exotic creatures kept in captivity for exhibition. Menageries first appeared with the advent of urbanization, when contact with wild animals became rare, and the keeping of exotics was almost exclusively the privilege of royalty and nobility. Mesopotamian kings, who received foreign beasts as tribute, created elaborate gardens to house them called paradeisoi, later to serve as the model for the biblical Garden of Eden. Egyptian pharaohs collected baboons, hippos, and elephants from sub-Saharan Africa and had them mummified to take into the afterlife. In the classical world, the Greeks brought back wild animals from military expeditions, a tradition their Roman conquerors continued, slaughtering the beasts in public arenas, a popular entertainment for nearly five hundred years. The Tower of London gained its famed royal menagerie in 1204. Across the Atlantic, Lord Moctezuma dazzled the first conquistadores with his magnificent pleasure gardens, replete with rare aquatic birds and wildcats tended by their own physicians. With the European discovery of the New World, the desire to own exotic animals intensified, and the Renaissance saw the invention of the private “cabinet of curiosities.” By the eighteenth century, the aristocracy was clamoring for monkeys and parrots as novel playthings.

The human species is unique in its compulsion to tame and nurture nearly all other vertebrate animals. In his 1984 classic, Dominance & Affection: The Making of Pets, the cultural geographer Yi-Fu Tuan characterizes this proclivity as an exercise in power—a kind of playful domination stemming from our desire to control the unpredictable forces of nature. According to Tuan, the keeping of pets reflects our hunger for status symbols, for what the philosopher Jean-Paul Sartre called the “carnal, clinging, humble, organic, milky taste of the creature,” which underlies all luxury goods.

The modern pet shop first appeared in American cities in the 1890s; and with it began the mass importation of exotic animals from Asia and South America. Pet-keeping in the United States exploded in the economic boom following World War II and, since the 1970s, has more than tripled. For the first time in history, more American households have pets than don’t, including some 86 million cats and 78 million dogs. But no one knows how many “exotics” there are, not least because no one agrees how to define an exotic pet. Does a native but wild animal like a skunk count? What about a potbellied pig? Further complicating matters, much of the trade operates underground, flouting state and federal laws.

In the 1980s, wild birds comprised the hottest segment of the black market. Next to take off was the “herp trade,” short for herpetoculture, which is the keeping of reptiles and amphibians such as turtles, lizards, and salamanders. “That’s where you have the big-buck items,” Fitzpatrick told me. He described how he once went undercover posing as a reptile collector to buy a critically endangered $18,000 radiated tortoise from Madagascar with a brilliant star pattern on its shell. As he was making the purchase, the dealer showed him a picture of a one-of-a-kind turtle—an albino river cooter, its entire body a pale jade white—and said he’d been offered $101,000 for the animal but was holding out for more.

On that occasion, wary of being searched, Fitzpatrick had slipped his gun into a drawer in another room, and when his backup team was delayed, he began to sweat. Though the dealer didn’t resist arrest, high-stakes turtle trafficking can be tied up with all sorts of unsavory behavior. Interpol warns that organized-crime networks use the same routes to smuggle animals as they do weapons, drugs, and people—that environmental crime goes hand in hand with corruption, money laundering, even murder.

•  •  • 

IT WAS FITZPATRICK who first told me about the Asian arowana. At the time, I still thought of pet fish as one step up from potted plants. Had someone informed me that fish comprise the vast majority of exotic pets—that they are the most common pet, period, with more than 100 million swimming in aquariums across the United States—I would not have cared one bit. If there was anything appealing about them, it was their comic irrelevancy and their association with childhood.

When I was little, my parents got a tank of goldfish as a sorry substitute for a dog or cat. One day when I was about six, I noticed bubbles escaping from the fish’s puckering mouths and wondered if they were talking to each other. Retrieving my Fisher-Price stethoscope, I pushed a chair next to the aquarium and climbed up to listen for tiny voices rising from the water’s surface. All I heard was silence. After that, I ignored them, and they continued to ignore me.

Not everyone, however, shared my dispassion. “One thing we deal with here in the city is a fish,” Fitzpatrick told me. “Arowana.” I misheard this as “marijuana,” and the association proved surprisingly apt. Protected by the Endangered Species Act, the Asian arowana cannot legally be brought into the United States as a pet. Yet trafficking is rampant across the country. Fitzpatrick recounted a bust at a dingy Brooklyn sweatshop, where women sat hunched over sewing machines, scraps of fabric strewn about the floor—a front for running fish. Another time, acting on a tip, he caught a Malaysian-born Queens man smuggling arowana through JFK Airport in water-filled baggies packed in a suitcase. Fitzpatrick noted that even the cheapest specimens sold for thousands of dollars, and prices went up from there, depending on coloration, the most desirable being red. “In certain Asian populations the arowana is considered good luck or a sign of prosperity or a status symbol,” he explained. “And it’s something that’s been overharvested for the pet trade for those reasons.”

The obsession with the fish, however, wasn’t limited to Asian cultures. There was, for example, the Wall Street banker who broke down crying after he was arrested for possession of the species, confessing he couldn’t resist its dark-alley appeal. “In recent years, we’ve seen more cases involving non-Asians—white people,” Fitzpatrick said. The previous summer, two Long Island men had been caught at the Canadian border, driving back from Montreal with four specimens swimming in the spare-tire well of their SUV. Then a young man was busted running arowana from his family’s home in the suburbs. Fitzpatrick theorized that selling black-market fish was considered safer than dealing in other high-value contraband such as drugs and guns—especially in New York, where just twenty environmental conservation officers cover the same territory as some thirty-four thousand NYPD.

The way he saw it, wildlife traffickers were motivated by pure greed, participating in what may well be the world’s most profitable form of illegal trade. But the collectors were driven by a passion he found easier to relate to. “I think that a lot of the people who have these animals are interested in nature, and that, in and of itself, is not a bad thing,” he said. “It’s just they’re going about it the wrong way.”

As a young graduate student in biology, Fitzpatrick had spent two months studying birds in the jungles of Venezuela, where he lost thirty pounds, grew “a full Grizzly Adams beard,” and got all sorts of weird skin infections before realizing he was really a city person. He still loved tropical animals—from afar. His only pet was a pint-size Maltese with a name he refused to disclose. “Like Snowball?” I asked.

“Something along those lines,” he said.

“Flufferbutter?”

“You get the picture.”

•  •  • 

THAT EVENING AFTER I got home, I looked up the Asian arowana to see what more I could find. Fitzpatrick had mentioned that the species was officially called the Asian bonytongue—“very unsexy name”—for a long bone of a tongue, bristling with prickly, pinlike teeth, which the fish uses to seize and crush prey against teeth on the roof of its mouth.

The bonytongues, I learned, are among the most ancient living fish on earth. The oldest fossils date to the Late Jurassic or Early Cretaceous and reveal giant creatures with ferocious fangs that roamed the prehistoric seas, preying on ichthyosaurs and plesiosaurs. Today the family Osteoglossidae (from the Greek osteo meaning “bone,” and gloss meaning “tongue”) no longer inhabits the oceans but rather the rivers and lakes of the earth’s tropical midsection, where it traditionally includes one of the largest of all freshwater fish: the Amazonian arapaima, which can grow nearly fifteen feet long and weigh some 450 pounds. With the exception of this giant, the rest of the family—all long, thin creatures armored in a mosaic of large, heavy scales—are commonly known as arowanas.

The most formidable among them (or at least the most acrobatic) is the South American silver arowana, also known as the water monkey for its ability to leap six feet into the air to snatch bugs, birds, snakes, and bats from overhanging branches. (Do not google arowana eats duckling.) In 2008, when a New Jersey man reached into a tank at Camden’s Adventure Aquarium to touch a silver arowana, the fish tried to make a meal of his hand. In his subsequent lawsuit, the victim alleged “painful bodily injuries” and that his three-year-old son suffered “severe emotional distress, headaches, nausea, long continued mental disturbance and repeated hysterical attacks” after witnessing the incident.

Despite or perhaps because of its ferocity, the silver arowana is a popular pet in the United States—and a perfectly legal one—with young fry selling for as little as $30 to $50 apiece. In all, there are seven recognized arowana species (with three more disputed among scientists) in South America, Africa, Southeast Asia, New Guinea, and Australia. Only the Asian variety is banned in the United States.

Overseas, however, the Asian arowana is an openly coveted commodity in a legitimate luxury market. “Forget oil and diamonds, the next big thing in Southeast Asia is fish,” I read in the hobbyist magazine Practical Fishkeeping, which described how fifty specimens collectively valued at a million dollars had been placed under twenty-four-hour guard in Jakarta, Indonesia. “While these fish may be disappearing in the wild, their popularity amongst Asia’s richest is ever increasing.”

In some instances, the species was reared on farms that could pass as prisons—facilities protected by nested walls, watchtowers, and rottweilers that prowled the perimeters at night. The reason for the heavy security became clear as I dug deeper into an international news archive that chronicled a spate of fish thefts across Southeast Asia. In Malaysia, five arowana stolen from a woman’s house were worth more than all her other possessions combined. Singapore, which boasts one of the lowest crime rates in the world, once reported four such heists in a single week. One thief punched out an elderly woman who chased him as he made off with her prized fish in a sloshing bucket. He was sentenced to three years in prison and twelve strokes of a wet cane.

As for who was taking the fish, some surmised that the thieves were fish lovers who could not afford the astronomical prices. Others suspected that a crime syndicate was behind the thefts—a sort of shadowy “fish mafia.” Bolstering this theory was a harrowing case in Indonesia, where an arowana dealer and his heavily armed cronies allegedly kidnapped and held for ransom a Japanese buyer.

Despite all this criminality, however, the trade in the farmed fish was legal not only in Asia but throughout most of the world, including Canada and Europe—the one major exception (other than the United States) being Australia, which bans the species to protect its own tropical fauna. A few years back, a forty-five-year-old housewife was arrested at the Melbourne Airport trying to enter the country with fifty-one fish, including an Asian arowana, hidden beneath her poufy skirt. “We became suspicious after hearing these flipping and flapping noises,” a customs official later told the press.

Such absurd tales of smuggling kept me up late as I pored over the hundred-some articles I’d printed out and spread across my living room floor. The picture that gradually emerged, however, looked less like the illegal drug trade and more like a parody of Manhattan’s overheated art scene, complete with record-breaking prices, anonymous buyers, stolen specimens, unsavory dealers, and even clever fakes. Whatever the best metaphor, it seemed the Asian arowana had a long history of driving human beings to dangerous extremes.

One summer in college, I’d read Jane Goodall’s In the Shadow of Man, and ever since, I’d dreamed of venturing into the jungle to write a great story about wildlife. Around the time my curiosity in the arowana began, I’d been awarded a fellowship intended to fund a reporting project abroad. Now I knew how I’d use it: I would go see for myself where all these smuggled arowana were coming from and what made the species so irresistible. Goodall had her noble, tool-wielding primates—I would have a bad-tempered, bony-tongued fish.

It was obvious where to start. At the center of the glamorous world of Southeast Asian aquaculture reigned a flamboyant Singaporean tastemaker known as Kenny the Fish, a chain-smoking millionaire fond of posing nude behind strategically placed aquatic pets. The Fish’s real name was Kenny Yap, and he was the executive chairman of an ornamental-fish farm so lucrative that it was listed on Singapore’s main stock exchange. Recently, the Singaporean press had dubbed him one of the city’s most eligible bachelors and called for him to host a national spin-off of Donald Trump’s reality show, The Apprentice. To enter his website, I had to click on his belly button.

I’ve since come to think of this navel as the rabbit hole into which I fell, not to emerge for some three and a half years.