A Tahitian black pearl necklace, missing for over eighty years, takes the thirteen-year-old Botanic Hill detectives—Lanny, Lexi, Moki, and Rani—from California to Oʿahu in one of the squad’s most baffling cases yet!

The teens’ famous elderly neighbor Mr. Itsuki Yamada hires them to find his family’s valuable heirloom necklace. Soon, they become embroiled in a complex mystery wrapped around the 1941 bombing of Pearl Harbor, World War II Japanese internment camps, an international surfing competition, sea caves, kidnappings, more thefts, an island cult inspired by a Japanese legend, and strange goings on in an abandoned pineapple shack.

Can the detectives prevent more crimes, avoid injury, and locate Mr. Yamada’s pearl necklace before it’s too late? Time matters—even in laid-back Hawaiʿi!