The Mystery of the Propitious Portal

A historic mutiny. A midnight clue. And a family history that time forgot.

Step into mysteries that demand courage, discernment, and the will to seek the truth. Conceived and co-written by the daughter of Robert Arthur - the creator of the Three Investigators universe - this restoration of the classic series takes its iconic characters into a new age, with gripping contemporary adventures for young readers who crave meaning, want to share in the growth of characters they admire, and seek a world they can return to again and again.

In the sixteenth book of a 26-book story arc, when The Three Investigators attend the wedding of their friends Charlotte Mitchell and Connor O'Malley at The Tahitian Ojai Resort in the Ojai Valley, they don't expect to get caught up in a mystery - especially not Bob, who has invited Freya Haldorrson to accompany him on their very first date. Even so, they soon hear about a stranger who tried to break into the resort's library the night before the wedding.

During a treasure hunt, one of the wedding activities, the boys also stumble upon a series of curious events that may or may not be linked to the attempted break-in. Winning the treasure hunt gives them a prize of three days and two nights at the resort, allowing them to follow the trail of clues at their leisure.

Along the way, they meet Otis Wyndham, the 93-year-old owner of a local bookstore, whose colorful past includes dating a burlesque dancer and working as a secretary to Charles Nordhoff, co-author of Mutiny on the Bounty. The resort's owner, it turns out, is obsessed with Nordhoff's history, and to their surprise, a young tennis pro named Heramana Adams is a direct descendent of one of the last surviving Bounty mutineers.

What starts as a simple puzzle turns into an investigation full of fascinating questions. Why did someone steal a book from the library only to return it the very next day? Where have the legendary Tahitian pearls that once belonged to Nordhoff disappeared to? What's the connection between tennis and this treasure hunt? Can Mallory's eidetic memory unlock the secrets hidden in a series of old photographs? As the Investigators' time at the resort draws to an end with the solution to the puzzle tantalizingly close, Jupiter has a dream that leads him out into the night - where a new revelation might just change everything.

Join Jupiter, Pete, Bob, and Mallory as they work to solve an 80-year-old mystery full of sinuous twists. As the story unfolds, you'll want to be there as families are reconfigured, villains turn out to be heroes, and a dastardly score in tennis turns out to be the guiding word.

Binding Type: Paperback
Publisher: Hollow Tree Press
Published: 06/03/2026
ISBN: 9781965321454
Pages: 316
Weight: 0.81lbs
Size: 8.50h x 5.50w x 0.71d