
The Secret of Terror Castle No. 1
1964
The Three Investigators set out to discover if Terrill Castle really is haunted. A good plot twist, that would be the envy of any thriller writer, turns the “predictable” story on its head. Great fun for a quiet evening.

The Mystery of the Stuttering Parrot No. 2
1964
While helping a retired actor find his beloved parrot, The Three Investigators uncover the theft of a priceless artwork. To recover both the parrot and the painting, they must find the other talking parrots and solve the riddle taught to them by John Silver. A good story that is well written, with a nice riddle the reader can have a go at before the lads solve it.
(The trio acquire Blackbeard, their mynah bird, in this book.)

The Mystery of the Whispering Mummy No. 3
1965

The Mystery of the Green Ghost No. 4
1965
Jupiter sends Pete and Bob to have a look at the Green Mansion, before it is torn down by developers. There they encounter the ghost of Mathias Green as it floats one last time through the house and wanders across town looking for a new haunt. Soon the ghost is seen at the vineyard of his niece, who ask for Bob and Pete to come and help. There the mystery is complicated by the involvement of an ancient Chinese man, seeking to acquire a string of pearls stolen years ago. A claustrophobic escape through an old mine rounds off a thrilling story.
(Chief Reynolds gives The Three Investigators the “Volunteer Junior Assistant Deputy” cards; and Bob no longer needs to wear the brace on his leg.)

The Mystery of the Vanishing Treasure No. 5
1966
1970, Armada Books, 0006905382 ·

The Secret of Skeleton Island No. 6
1966
Alfred Hitchcock asks The Three Investigators to look into the troubles at the movie set on Skeleton Island. From the start it is obvious that someone wants both them and the movie crew off the island, but when the ghost on the merry-go-round appears Jupiter is set to solve the mystery. The trio also meet a young lad on a treasure hunt and decide to help him solve the riddle of Captain One-Ear and his lost doubloons. A good adventure, with Pete and Bob taking centre stage and Jupe sitting out due to a cold.

The Mystery of the Fiery Eye No. 7
1967
1971, Armada Books, 0006907008 ·

The Mystery of the Silver Spider No. 8
1967
The Three Investigators are invited to visit their new friend Djaro, the prince of Varania, in Europe and are also asked by the U.S. Government to act as friendly “spies” to prevent any trouble. Then the Silver Spider, the emblem of the country, is stolen and the boys are framed for the theft. Great adventure, with a good smattering of international espionage to make the story even more exciting.

The Mystery of the Screaming Clock No. 9
1968
A clock that screams, instead of ringing, sets the trio on an investigation to clear a man falsely accused of stealing priceless artworks and to find the other paintings by solving the mystery of the screaming clock. A good story with an excellent riddle.
The character of Huganay makes his second and, sadly, last appearance in the series, but his escape from arrest by the police is one of the best ever written. It just oozes confidence and contempt.

The Mystery of the Moaning Cave No. 10
1968
1972, Armada Books ·

The Mystery of the Talking Skull No. 11
1969
When Jupiter buys an old trunk at an auction, the boys find a talking skull inside and clues to where the loot from a bank robbery is hidden. Other shady characters are also after the money and soon it becomes a race to solve the mystery. A good entry in the series, with two nice riddles for the reader to have a go at before Jupiter solves it.

The Mystery of the Laughing Shadow No. 12
1969
1973, Armada Books, 0006907016 ·

The Secret of the Crooked Cat No. 13
1970
1973, Armada Books, 0006907008 ·

The Mystery of the Coughing Dragon No. 14
1970
The Three Investigators go to Seaside to search for a missing dog, but instead find a dragon living in the cliffs next to the beach. A thrilling story that puts the trio a few times in dangerous situations. The ending is a good conclusion, with everything making perfect sense.

The Mystery of the Flaming Footprints No. 15
1971
1988, Armada Books, 000690890X ·

The Mystery of the Nervous Lion No. 16
1971

The Mystery of the Singing Serpent No. 17
1972
The Three Investigators reluctantly agree to help Allie Jamison – the girl down the street – get rid of an unwanted guest. A rather dark entry in the series, with the occult featuring prominantly. Not recommended for very young readers due to its content, but still a good book.

The Mystery of the Shrinking House No. 18
1972
1978, Armada Books, 0006911919 ·

The Secret of Phantom Lake No. 19
1973

The Mystery of Monster Mountain No. 20
1973

The Secret of the Haunted Mirror No. 21
1974
Worthington introduces the trio to Mrs Darnley, who had just acquired a strange mirror with a sinister past. A rival collector warns of an evil curse and soon after the sorceror Chiavo is seen inside the mirror, laughing and taunting the household. The investigations also uncover a polical plot against a foreign nation. A very good entry in the series, with some scary moments when the mirror comes to life.

The Mystery of the Dead Man's Riddle No. 22
1974
Dingo Towne leaves a fortune in gems to whoever can find it by solving the riddle. The Three Investigators are hired by his daughter-in-law, but it’s more difficult than it looks. Soon nasty relatives arrive and the boys are shadowed by two unsavioury characters. Skinny Norris also gets in on the act and repeatedly mess things up badly. A good adventure, with one of the best riddles and a darling of a plot twist.

The Mystery of the Invisible Dog No. 23
1975
1979, Armada Books, 0006915671 ·

The Mystery of Death Trap Mine No. 24
1976
Allie Jamison invites The Three Investigators to spend the summer on her uncle’s Christmas tree farm near Twin Lakes. She believes that Wesley Thurgood, new owner of Death Trap Mine, is a phony and wants the trio to help her prove it. Things get interesting when Jupiter finds traces of gold in the mine and Allie stumbles on a skeleton in one of the shafts. Somehow an armoured car robbery of five years previously also fits into the picture. Why else is Thurgood so interested in a played-out silver mine? A fast-paced adventure that never lets the reader go. Well worth a read.

The Mystery of the Dancing Devil No. 25
1976

The Mystery of the Headless Horse No. 26
1977
1984, Armada Books, 0006918611 ·

The Mystery of the Magic Circle No. 27
1978

The Mystery of the Deadly Double No. 28
1978

The Mystery of the Sinister Scarecrow No. 29
1979
1983, Armada Books, 0006921027 ·

The Secret of Shark Reef No. 30
1979
1983, Armada Books, 0006921531 ·

The Mystery of the Scar-faced Beggar No. 31
1981

The Mystery of the Blazing Cliffs No. 32
1981
The Three Investigators find adventure and mystery when they make a routine delivery for the Salvage Yard to a ranch. The owner believes that the current order will be destroyed and has turned the ranch into a self-sufficient community, whilst his wife believes that extra-terrestrials will soon come to save the world. Then the army closes all roads and inform the residents that some national emergency has been declared; and a flying saucer is seen landing in the meadow. Not the best, but still a good story.

The Mystery of the Purple Pirate No. 33
1982
The Society for Justice to Buccaneers, Brigands, Bandits, and Bushwackers calls for tales about their “members” and the trio are enthusiastic to help. Strangely, however, the society is only interested in the Purple Pirate. Captain Joy’s stories to be exact, not when Jupiter tried to recount it. The Three Investigators delve deep into Californian history and come up with an old mystery linked to modern thieves. A good story, characters with dubious loyalties, suspense filled climax and a wonderful plot twist make this a good entry in the series.

The Mystery of the Wandering Caveman No. 34
1982

The Mystery of the Kidnapped Whale No. 35
1983

The Mystery of the Missing Mermaid No. 36
1983
Armada Books ·

The Mystery of the Two-toed Pigeon No. 37
1984
Armada Books ·

The Mystery of the Smashing Glass No. 38
1984
Armada Books ·

The Mystery of the Trail of Terror No. 39
1984
The Three Investigators accompany Pete’s grandfather on a cross-country trip to New York, where he intends to sell his latest invention. Why is his neighbour following them? Is he after the invention? Things become hairier as the travellers near their destination, with several outright attempts at theft, sabotage, kidnapping and possibly murder. The unfolding of the plot is weak, with several irrelevant characters and situations, like the biker gang and the woman in South Dakota. Every series has its clunker and this is it.

The Mystery of the Rogues’ Reunion No. 40
1985

The Mystery of the Creep-show Crooks No. 41
1985

The Mystery of Wreckers’ Rock No. 42
1986

The Mystery of the Cranky Collector No. 43
1987
“Fan Fiction”

The Case of the Fourth Investigator
2006
Jupiter and Worthington attend the auction of a lost Arthur Conan Doyle manuscript recently discovered in nearby Seaside (see The Mystery of the Coughing Dragon). After reading the first page, Worthington deduces that it is a forgery and challenges the reader on how he knows this. Excellent, although the give-away clue is somewhat obvious to any cricket fan.
The e-book can be downloaded from The Three Investigators ??? U.S. Editions Collector Site.

The Mystery of the Hitchcock Inheritance
2006
The story takes place just after The Secret of Shark Reef. The Three Investigators have just lost their mentor, Alfred Hitchcock, and are feeling somewhat dejected and without hope. Only it seems that Hitch has one last game to play with them — in the form of a riddle in his will. The trio set out to solve the conundrum, but are hampered in their efforts by others claiming the treasure for themselves.
The e-book reads easy, but is without depth. As can be expected from “fan fiction”, there are many references to various T3I stuff, like the name of the embassy official (R. Arthur) and the Kingdom of Varania (of which the use thereof by the author is in my opinion somewhat contrived). The weak riddle and inconsistencies notwithstanding, the story is an enjoyable way to spend an hour or two in the company of our favourite sleuths.
The e-book can be downloaded from The Three Investigators ??? U.S. Editions Collector Site.

