The Sherlock Society

The next morning, Grandpa loads shovels and a metal detector into his Cadillac convertible, Roberta. During the drive to Palm Island, Lina shares anecdotes about her Wyoming upbringing, including winning a belt buckle in an egg-drop competition.

At the Palm Island gatehouse, Grandpa demonstrates the reporter’s skill of getting in the door. He presents Officer Jensen with a Sherlock Society business card and fabricates a story about delivering divorce documents to a confidential client, using the children as cover so as not to arouse the client’s husband’s suspicion. Jensen grants them entry.

At 93 Palm Avenue, they discover Capone’s house has been demolished. Only the swimming pool and two tall royal palm trees remain on what is now a construction site. Yadi photographs the remnants and suggests a nighttime trespassing operation, referencing his role in a Pizza Impossible commercial. Grandpa vetoes this plan, explaining that trespassing to dig on private property would be illegal and anything found would belong to the current owner.

They proceed to Coconut Grove to interview Virginia Jackson, granddaughter of Capone’s gardener. At her bungalow, Grandpa establishes credibility by recalling specific details about her grandfather’s funeral. Ms. Jackson reveals that several treasure hunters have approached her before, but Grandpa is the first to prove he genuinely knew Mr. Thomas.

Inside Ms. Jackson’s home, she negotiates terms: if they find the treasure, she receives a one-quarter share to donate to a library literacy program. Grandpa agrees, and she allows the children to conduct the interview.

Ms. Jackson explains that her grandfather preferred the term plantsman to gardener, considering his work a spiritual calling. A University of Miami botanist once recorded a three-hour interview with him because his self-taught knowledge was extraordinary. He used natural solutions—banana peels, coffee grounds, seaweed, even fermented fish guts—instead of commercial chemicals. The Capones treated him with dignity at their dinner table, while Miami’s “respectable” citizens enforced segregation against him.

She confirms her grandfather often speculated about the treasure and its animal guardians, though the species varied with each telling. Critically, he was certain the money was not buried on the Palm Island estate. After Capone’s release from Alcatraz with severe cognitive decline, his niece Deirdre Capone had Mr. Thomas methodically excavate the entire property. They found nothing.

Ms. Jackson produces her grandfather’s plant diary, filled with meticulous entries using location codes: PI for Palm Island and KB for Key Biscayne, where Capone maintained plant nurseries. Lina observes that Latin botanical names appear only from late 1931 onward. Ms. Jackson retrieves the answer: Elements of Botany, inscribed by Capone on September 28, 1931—the week before his trial. The inscription includes Matthew 6:21; Lina finds the verse, which states that where one’s treasure is, there one’s heart will be also. She concludes it is a coded message.

The group gathers around Ms. Jackson’s dining room table to examine the botany book. Zoe theorizes that Capone intended Mr. Thomas to safeguard the book itself, using it as a secure hiding place. Recalling a clue hidden in a book spine during a school escape room, Alex suggests checking the binding. Lina carefully opens the spine and discovers a folded piece of onionskin paper.

The paper reveals a hand-drawn map showing a finger-shaped landmass with an X marked near the top. Lina confirms Capone drew it by matching the distinctive loop in the letter C. Using her phone, Zoe translates the Italian annotations: “Chiave” means “key,” while the words around the X—“orsi, scimmie, pantere, and alligatori”—translate to “bears, monkeys, panthers, and alligators,” confirming the wild animal clue. The word “frontespizio” means both “title page” and “frontispiece.”

Lina realizes the translucent onionskin functions as an overlay. When she aligns the map with the frontispiece illustration of palm trees, the X marks the base of two royal palms. The group concludes key has dual meaning: it identifies an island (like Key Biscayne) and serves as an answer key through the overlay technique. Yadi’s photographs show that the same type of royal palms remain at the Capone estate, and he suggests checking the plant diary to find where those trees were originally transplanted from. When Lina jokes that the zoo has those animals but isn’t on an island, Grandpa and Ms. Jackson laugh—the original Miami zoo was located on Key Biscayne.

They drive to Crandon Park on Key Biscayne. Grandpa explains that Hurricane Betsy flooded the original zoo, killing many animals. The zoo relocated inland in 1980, but remnants of the old enclosures remain as a peacock preserve and public garden.

Walking past the former lion, tiger, and gibbon exhibits, they reach the old monkey enclosure. Adjacent to it, Zoe spots a small lake containing a tiny island with two palm trees—a perfect match for both the book illustration and the “island on an island” clue. Grandpa heads to retrieve shovels from the car.

Lina halts everyone, pointing to a mural on the enclosure wall commemorating “Crandon Park 75th Jubilee Celebration.” Grandpa realizes his error: if the park is celebrating its seventy-fifth anniversary, it didn’t exist during Capone’s era. Zoe confirms on her phone that the zoo opened in 1948, one year after Capone’s death and 17 years after the treasure was buried. Dejected, they return to the car with another dead end.

Back home, the discouraged group discusses the case. A conversation about Cuban sodas—Ironbeer and Materva—makes Lina feel like an outsider. Alex questions the ethics of keeping money from criminal activity. Their mother, Melinda, enters and reveals she knows about the treasure hunt. After a tense exchange with Zoe, she explains that she approves of them investigating a historical mystery under Grandpa’s supervision. As an attorney, she clarifies that Florida law would require them to report any treasure and accept a finder’s fee of ten to fifteen percent, netting roughly ten to fifteen thousand dollars each after splits and taxes.

Their father invites Yadi and Lina to stay for paella. During dinner, Zoe sits beside her mother in an unspoken truce. Lina explains that her family moved from Wyoming after her parents’ divorce. Dad shares his own story of childhood rebellion following his parents’ divorce, which eventually channeled into his passion for marine biology. The conversation returns to the treasure hunt, and Dad suggests investigating the Lost City, Capone’s moonshine operation in the Everglades. Zoe researches on her phone and discovers the hideout was located on an island of higher ground accessible by wagon—matching all their clues: an island reachable without a boat, surrounded by wild animals.

Following Grandpa’s rule about homework before fieldwork, the group spends two days researching the Lost City. They divide responsibilities using their assigned Ws: Alex searches for geographic details, Yadi examines the plant diary for Everglades references, Lina tracks down sources, and Zoe constructs a timeline. They narrow the search to a two-by-four-mile rectangle in western Broward County on the Miccosukee reservation, accessible via dirt roads off Alligator Alley.

On the third morning, they present their findings to Grandpa, showing him a grid map dividing the search area into eight one-square-mile sections. Yadi proposes modernizing Grandpa’s methodical search technique by using his drone to systematically survey each grid. Grandpa approves the plan and tells everyone to prepare for an Everglades expedition.

Before heading out, they make stops at Yadi’s and Lina’s homes to retrieve the drone and allow wardrobe changes, then visit a Cuban coffee shop for provisions. Their final stop is outside Marjory Stoneman Douglas’s former cottage. Grandpa explains that she was the Everglades’ greatest advocate, coining the phrase “River of Grass” to describe it. He credits her with providing guidance during his early reporting career.

The group drives north to Alligator Alley, the highway cutting across the Everglades. During the ride, Yadi shares his theory that the unusually tall fences are designed to contain the skunk ape, Florida’s version of Bigfoot, rather than just alligators. At Bailey’s Bait & Tackle Shop, the owner claims he has seen the creature twice, reinforcing Yadi’s belief.

They reach their search zone along the L-28 canal on the Miccosukee reservation. Grandpa warns about Burmese pythons, explaining that thousands infested the Everglades after Hurricane Andrew destroyed a breeding facility in 1992. Yadi launches the drone, and Alex attempts to mark searched areas on a map. However, the monotonous landscape makes accurate tracking nearly impossible.

The search quickly becomes miserable. Heat, humidity, and relentless mosquitoes plague them despite long sleeves, pants, and bug spray. They struggle for a full day with little progress, then repeat the process for two more days. By the third afternoon, frustrated and exhausted, they agree to abandon the Capone investigation in favor of researching Murf the Surf instead.

As they prepare to leave via Snake Road, Lina notices a faint path of tire tracks branching off into tall grass. She convinces the group to investigate one final time.

Following the tire tracks for nearly a mile across flat grassland, they reach wooded terrain where the ground becomes too mucky for Grandpa’s convertible to continue. They proceed on foot through squishy soil until they spot a clearing ahead. Beyond the tree line lies a three-acre island in the middle of a slough—matching the Lost City description perfectly.

As they investigate, a foul stench overwhelms them. They discover a dead alligator floating on its back, several dead fish, and a wood stork carcass. Lina identifies the cause: a pile of illegally dumped industrial waste, including three metal drums, creating toxic gray sludge in the water. Grandpa immediately orders everyone back to the car for their safety. He examines tire tracks in the muck, identifying two sets from a truck and trailer—evidence of dumpers backing up to unload.

Yadi uses his last drone battery to document the dump site and dead wildlife. Alex suggests collecting a water sample. Using Grandpa’s fishing pole with a bottle tied to the line, they retrieve contaminated water without approaching the hazard.

At the Miccosukee Police Department’s Alligator Alley Precinct, they report the crime to Officer Gonzalez and provide drone footage. The officer explains that jurisdictional limitations and budget constraints hinder effective investigation when perpetrators operate off tribal land. As they leave, Grandpa declares the treasure hunt over due to safety concerns. Zoe disagrees, arguing that the century-old treasure can wait. Their mission now is finding the polluters and gathering evidence for authorities. She says their reward will be doing what is right, not what is easy. Alex realizes in this moment that his sister has truly returned.