HH1. The Happy Hollisters
The adventures begin when the Happy Hollisters move into their new house in Shoreham, but the moving van carrying their toys disappears. Then they learn that their house may be haunted, with a treasure hidden somewhere inside!
HH2. The Happy Hollisters on a River Trip
A fishing contest at The Trading Post, Mr. Hollister’s sporting goods store, has everybody in Shoreham excited. After Pete catches a large fish with a mysterious tag on its tail, another adventure begins for the eager young detectives.
HH3. The Happy Hollisters at Sea Gull Beach
The Happy Hollisters are looking forward to vacationing at Sea Gull Beach with their cousins. Then they discover that the lighthouse lamp they received as a gift from Uncle Russ contains a tiny treasure, and are even more eager to get to join their relatives and search for the rest of the treasure.
HH4. The Happy Hollisters and the Indian Treasure
Mr. Hollister plans a trip to New Mexico to purchase SW Indian trinkets to sell at The Trading Post. When family friend and Yumatan Indian Indy Roades tells them of his tribe’s lost turquoise mine, Mr. Hollister brings the whole family along to help locate the lost gems.
HH5. The Happy Hollisters at Mystery Mountain
The Happy Hollisters are invited to stay on a ranch in New Mexico and discover a map leading to the cave of ancient dollmakers, the long-lost buried secret of the mountain. The Happy Hollisters help find the lost cave and discover a sheep rustling ring in this fast-moving story.
HH6. The Happy Hollisters at Snowflake Camp
The Happy Hollisters head to Canada to visit their grandparents for the yearly Trappers’ Carnival and end up joining the search for a missing dog trainer and some valuable Eskimo puppies. In addition to solving the mystery, they have great fun learning to ski and drive a dog sled.
HH7. The Happy Hollisters and the Trading Post Mystery
There is great activity in the Hollister household upon the arrival of Domingo, the donkey promised Sue by friends in New Mexico. The excitement mounts higher with the discovery of a note attached to the donkey’s halter signed “Y.I.F.” So begins one of the two mysteries that run through this book.
HH8. The Happy Hollisters at Circus Island
A trip to Circus Island in Florida in search of a houseboat to purchase puts the Happy Hollisters on the trail of circus dog thieves. As the young sleuths uncover sinister goings-on behind the scenes at the circus, they also learn exciting circus tricks like tumbling and tight-rope walking.
HH9. The Happy Hollisters and the Secret Fort
A missing letter is the key to the whereabouts of Fort Freedom, the stockade that disappeared after the Revolutionary War. The fort is located somewhere within the boundaries of Shoreham and has been sought after for many years, not only for its historic value but for the gold supposed to be hidden there by the early settlers.
HH10. The Happy Hollisters and the Merry-Go-Round Mystery
Pete Hollister volunteers to locate a merry-go-round for the Lincoln School fair. Disappointments abound when a gear for the apparatus is apparently lost and a vandal sets fire to the booths and decorations in attempt to ruin the event.
HH11. The Happy Hollisters at Pony Hill Farm
The Happy Hollisters are surprised to learn that a hobbyhorse they purchased at an auction holds the key to settling an inheritance that will change the future for their new friend, Graham Stone. The mystery deepens with the appearance of a beautiful appaloosa pony, seemingly out of nowhere.
HH12. The Happy Hollisters and the Old Clipper Ship
The Hollisters are on their way to Boston on the trail of a long-lost ship captain’s log. Famous movie star Gregory Grant is also headed east to star in a movie about clipper ships. He invites the children to come along, offering them parts in the movie while they search for more clues!
HH13. The Happy Hollisters at Lizard Cove
The arrival of a crate of pineapples and an odd pet at the Hollister home leads the family on a Puerto Rican vacation. A stone found on a sightseeing tour then proves to be a clue to a pirate’s treasure. The children have fun learning new customs and a new language as they comb the island for clues.
HH14. The Happy Hollisters and the Scarecrow Mystery
Mr. Hollister’s sporting goods and toy store, The Trading Post, is robbed, but the only things taken are a Geiger counter and some axes. His new invention, an inflatable canoe, is left untouched. The family leaves the matter to the police and heads to a nearby forest for a camping trip and test run of the canoe.
HH15. The Happy Hollisters and the Mystery of the Totem Faces
This story finds the Hollister family off to Alaska with Uncle Russ and their two cousins, Teddy and Jean. Russ Hollister, a commercial artist and cartoonist, has run out of ideas and is trying to think of a new location for his comic strip characters.
HH16. The Happy Hollisters and the Ice Carnival Mystery
Gram and Gramp Hollister invite the Hollister children to visit Québec for Mardi Gras and the annual Winter Carnival. Their visit coincides with the strange disappearance of a master sleigh maker, and the children set out to find him and experience new adventures in a most interesting and historic location.
HH17 The Happy Hollisters and the Mystery in Skyscraper City
A mysterious Chinese message tucked inside a book about New York City tunnels leads the Happy Hollisters to Chinatown in search of a long-lost treasure. While Mr. Hollister works with a toy manufacturer to perfect a new invention, the rest of the family explores New York City and learns about the Chinese way of life in Manhattan.
HH18. The Happy Hollisters and the Mystery of The Little Mermaid
On their first adventure outside of the Western Hemisphere, the Happy Hollisters travel to Denmark for their summer vacation. During the flight to Copenhagen, the children meet a member of the Danish royal family's staff who is carrying a valuable reproduction of the "Little Mermaid," the famous statue that overlooks the harbor in Copenhagen. Upon landing in Denmark, the figurine goes missing, and the sleuthing begins!
HH19. The Happy Hollisters and the Mystery at Missile Town
The Happy Hollisters arrive in Florida to visit their cousins and Uncle Walt, a rocket expert at Patrick Air Force Base. They are immediately caught up in a mystery when an unmanned missile explodes and the rocket’s valuable nose cone is lost in the ocean. The Hollisters race against time—and a villainous band of treasure hunters—to see who will find the missing payload first.
HH20. The Happy Hollisters and the Cowboy Mystery
Flickering lights on a mountaintop lure the Happy Hollisters to Nevada to solve a mystery on the Tumbling K Ranch, the home of their friends Bunky and Gina Blair. The mystery deepens when they cross paths with antelope poachers and hear rumors of buried gold, and the Happy Hollisters spend many happy hours on horseback searching for clues to solve all of the mysterious goings-on.
HH21. The Happy Hollisters and the Haunted House Mystery
GHOST HUNTER WANTED TO RID A HAUNTED HOUSE OF SPOOKS! APPLY MRS. NEELY. THE ANTIQUE HOUSE. Their curiosity aroused over this unusual advertisement, Pete and Pam Hollister visit Mrs. Neeley to apply for the job.
HH22. The Happy Hollisters and The Secret of The Lucky Coins
Learn what makes a coin “lucky” in The Happy Hollisters and the Secret of the Lucky Coins by Jerry West. Little Sue Hollister gets a valuable old coin as a reward for a good deed, and the whole family takes up the fascinating hobby of coin collecting. In the tangled roots of an old tree uprooted by a small tornado, Pete finds another rare coin marked with two mysterious clues, leading the children on an exciting and educational treasure hunt that combines coin collecting with botany and forestry.
HH23. The Happy Hollisters and the Castle Rock Mystery
An abandoned rock quarry, mysterious flying objects, and a valuable deposit of titanium lead the five Hollister children — Pete, Pam, Ricky, Holly, and Sue — into their latest thrilling adventure.
HH24. The Happy Hollisters and the Cuckoo Clock Mystery
It was a small note—written in German. Pete Hollister found it hidden in the door of a broken cuckoo clock. When the note was translated, the Hollister children were jubilant. The message was a riddle that made little sense to them—but it was the first clue in a brand-new mystery.
HH25. The Happy Hollisters and the Swiss Echo Mystery
High in the Swiss Alps, a suspicious stranger in a cable car dropped a large black key which the Hollisters found. An insurance investigator named Johann Meyer was following the stranger, an international jewel thief. Mr. Meyer told the Hollisters about his dangerous case—to find a large diamond that had been stolen from Holland. When Mr. Meyer’s small plane was reported missing over the mountains, the Hollisters decided to help. Clue piles on clue as the irrepressible Hollisters track down each new lead, learn about Swiss life and customs, rescue Mr. Meyer, and recover a valuable diamond.
HH26. The Happy Hollisters and the Sea Turtle Mystery
One day Pete and Pam Hollister rescued a Seminole Indian named Charlie Tiger Tail from drowning in Pine Lake. But they never dreamed that their heroic act would lead to a new, exciting mystery and a vacation in Florida. There were many more thrilling adventures—including Ricky’s capture by a gang of thieves who were illegally killing giant sea turtles and stealing their eggs!
HH27. The Happy Hollisters and the Punch and Judy Mystery
In this thrilling new adventure, the Happy Hollisters travel to the beautiful land of Italy to help their new friend, Nada Boschi find her Uncle Giovanni, a famous toymaker and puppeteer who has disappeared from his house in Rome. The Happy Hollisters have all kinds of adventures touring many famous places in Italy. And, before their trip has ended, they not only find Uncle Giovanni but help the Italian police round up a gang of dangerous thieves!
HH28. The Happy Hollisters and the Whistle-Pig Mystery
As the Happy Hollisters set out on a trip to historic New England, they learn that masked bandits have stolen almost a million dollars—and a carved wooden Indian has disappeared from a museum in the same town! Along the way, the children befriend a family of groundhogs, or “whistle-pigs,” never suspecting that these adorable little creatures will play a part in solving both mysteries.
HH29. The Happy Hollisters and the Ghost Horse Mystery
From the moment The Hollister children arrive on Wicket-ee-nock Island with Indy and Emmy Roades, it’s evident that someone doesn’t want them there at all. Prowlers, sabotaged boats, fake telegrams, and ghostly horses all conspire to send them back to Shoreham before they can find a valuable diamond-encrusted coat of arms that is at the heart of the mystery.
HH30. The Happy Hollisters and the Mystery of the Golden Witch
Spooky things are happening in Shoreham as Halloween approaches . . . the Hollisters stumble on an ancient gravestone with a cryptic message about a hidden treasure, and a mysterious stranger is snooping around the countryside for a golden weathervane in the shape of a witch on a broomstick. Fun and frights abound as the children work together to solve these intertwined mysteries!
HH31. The Happy Hollisters and the Mystery of the Mexican Idol
Uncle Russ is headed to Mexico to gather research material for his cartoon strip, and he invites the Happy Hollisters to join him when his map showing the location of the long-lost Temple of the Laughing Idol is stolen. Deep in the jungles of Yucatan, they stumble upon the ancient monument and discover a ring of smugglers who are looting valuable artifacts.
HH32. The Happy Hollisters and the Monster Mystery
Is Pine Lake a haven for creatures from outer space? The citizens of Shoreham are rattled by mysterious UFO sightings, but the Shoreham Detective Club is on the case. From unusual footprints in the mud to a doll stolen from the new “toy library” at school, the clues start piling up fast as The Happy Hollisters and their friends search for who—or what—is causing the panic around town.
HH33. The Happy Hollisters and the Mystery of the Midnight Trolls
A letter arrives for the Happy Hollisters from Gram Hollister, but it’s written in braille, a special code used by blind people. When they decipher the message, they learn that their help is needed solving the mystery of some “midnight trolls” who are making mischief for Gram. The trolls’ trail leads all the way to Iceland, where Mr. Hollister will be testing his new sailplane invention in an international meet. Norse myths combine with mystery in this exciting adventure, the final volume in the original series.