Foe Yay: A bit disturbingly, Huganay towards Jupiter in "The Mystery of the Screaming Clock." As the book was originally published in the late 60s, at least part of it is due to changing standards of what is viewed as appropriate behavior towards a young teenage boy, and it seems as though the writers were merely aiming to characterize Huganay as Affably Evil. Nevertheless, Huganay, described as "dapper" and "debonair," always seem to be "whispering into Jupiter's ear," and "wrapping his powerful arms" around Jupiter to hold him still and putting a hand over his mouth to stop Jupiter from yelling for help. He alternately speaks "softly" and "mockingly" to Jupiter, whilst seeming to relish in the advantage he gains over him.
He's quite flattering toward Jupiter, as if he's deliberately trying to be charming, addresses Jupiter with various fond epithets such as, "my boy," and "my plump but clever young friend." He also places a hand "earnestly" on Jupiter's shoulder and tells him, "I like spirit in a boy," while assuring Jupiter that their teamwork would be brilliant if they were to work together. Additionally, Huganay bestows Jupiter with various compliments, referring to the Three Investigators, (which he knows was Jupiter's creation) as "an ingenious organization," and telling Jupiter, "Your mind hums like a top."
Considering Jupiter is somewhere between the ages of 13-15 and Huganay is an elite adult criminal whose sincerity is doubtful, it can be slightly uncomfortable.
Genius Bonus: On numerous occasions, Jupiter's intellect and knowledge base allow him to make connections and deductions that most readers in the target demographic wouldn't be familiar with—Shakespeare is the most obvious example, since the famous Hamlet soliloquy quote appears in Stuttering Parrot, while Puck, the pseudonym used by Harold Thomas in Magic Circle, is how Jupiter identifies him as the missing Charles Goodfellow. Anything on the supernatural in the M.V. Carey books actually counts as this, but in general the series authors tend to include all manner of intriguing and informative details in the stories, usually connected in some way to unmasking the criminals or solving the mystery, though not always. Other examples would be:
"John Silver" from Stuttering Parrot (and for that matter, the names of all of the parrots).
The Augustus/Octavian bust mix-up in Fiery Eye.
The kookaburra from Laughing Shadow.
Francois Fortunard's lost masterpiece from Shrinking House (which is based off the missing Franz Marc painting "The Tower of Blue Horses").
The history of Fremont's expedition in California during the Mexican War in Headless Horse.
The bit with Indonesia once having been a Dutch colony being how Harold Thomas, who ate at an Indonesian restaurant, was revealed as Charles Goodfellow, original native of Holland, in Magic Circle.
The lone World War II submarine attack by Japan on the California coast, after Pearl Harbor, which forms the backstory for the hero and villain of Shark Reef.
Mr. Bonestell of Scar-Faced Beggar, who shares a name with hugely influential astronomy artist Chesley Bonestell (after whom the Association of Science Fiction and Fantasy Artists named their annual awards for artistic achievement, given every year at the World Science Fiction Convention). Appropriate for a book in which psychic dreams turn out to be real.
Germans Love David Hasselhoff: The series is hugely popular in Germany, where several authors have added many books not found in the original American series. (In German, they are called Die Drei ???, which is pronounced Die Drei Fragezeichen, which in turn means The Three Question Marks.) Furthermore, Germans love the Audio Adaptation of The Three Investigators. The voice actors of the three heroes (who were never swapped out, in spite of the audible change from kid to adult voices during the series' run), even can be considered celebrities in their own right. There have been release parties, during which fans meet to hear the newest play, and at this point there have been three stage shows with a fourth one upcoming in 2014. There have also been two German-produced films starring American actors as the trio and filmed in English, with South Africa playing the US - The Three Investigators and the Secret of Skeleton Island (2007) and The Three Investigators and the Secret of Terror Castle (2009).
Also the series is so popular that the 2009 stage adaptation of Screaming Clock drew over 15000 people into the Waldbühne (forest stage) open air amphitheatre in Berlin to listen to the three voice actors play out one of their classic episodes and set the world record for attendance to a single show of a live audio adaptation. In 2014 they managed to break their own record, with an original story written only for the tour and did so by cramming 20000 people into the Waldbühne.
The movies are very unpopular with the fanbase, though, because the fans felt that they are not true to the source material at all.
Harsher in Hindsight: Thanks to the numerous dangerous and extremely tense events which occur during Shark Reef (violent protests, kidnapping, a hurricane that nearly destroys the oil platform while Jupe and Pete are aboard, sharks, Gonda basically being a Yakuza-lite), Hitchcock (as the chapter title says) pleads exhaustion. This turns out to be the very last book he ever appears in, as after this is when the Real Life Hitchcock died.
Somewhat related to Germans Love David Hasselhoff since the Audio Adaptation of the Three Investigators is hugely popular in its own right, arguably even more so than the actual books. Due to its long running time (well over 30 years) the voice actors have developed sort of their own spin on the titular investigators and over the years it has deviated quite a bit from the original source material. All the while influence from the show started creeping into the newer books too, largely because the young authors of said books grew up with the show that is in turn based on the books they're now writing. Confused yet? So what does all this have to do with Ho Yay? Simple. These are the two voice actors of Peter and Bob, in a live stage audio adaptation, of the Three Investigators in character. This is the tame version to boot—there is an outtake where 'Bob' outright dipped 'Peter' in a very passionate kiss and full body embrace. To put it in Andreas Fröhlich aka Bob's words : "I think Jens (Peter) finally expected tongue action that night." Cue curious editor asking if he (Jens) got it. No. But he did imply that he groped him.
To the point that whenever Jeffery is mentioned in newer episodes, Bob gets extremely jealous of him much like a boyfriend jealous of someone's ex.
Also the show tended to shift lines from Kelly to Bob even before she left the show, leading to a moment where Bob is pretty much having a mini meltdown about his 'friend' note In German boyfriend and friend is covered by the same word and it becomes clear from the context which one is meant mostly, making this one very ambiguous. being missing, while Kelly calmly sat by not concerned in the least...
As of Episode 163 we have an 'on screen' kiss between the two after Peter solves the puzzle of the day, which was led up to by this exchange:
Peter : ...get it?
Bob : (excited)OF COURSE! Oh Pete, I could kiss you!
Peter : (embarrassed) Ehrm....not...not here... (They go on explaining the puzzle)
Jupiter: You solved it, Second!
Bob : (slightly breathy) Can I kiss you now?
Peter : Go ahead! *cue smoochie sounds*
Magnificent Bastard: Hugenay, at least in Screaming Clock. He pursues Bob and Harry to steal the clock, then disappears just in time for the cops to take them in for speeding, then has the audacity to steal it from their car while they're in the station. He slips a tracking device in Jupiter's coat pocket just before he goes to join Carlos, Gerry, and Jeeters so that, even when they lose him in traffic, he's able to find where they are and break in—with cops to arrest them. Except they're actually his own men merely dressed as cops. And then at the climax, when it seems he's about to escape with the missing paintings, the real police show up...only because the paintings have been found without being stolen, all the damage done to the house was with Harry's mother's permission, and even the "cops" can't be charged with impersonating the LAPD because their uniforms are mere Halloween costumes (and of NYPD officers), he can't be arrested for anything and walks off scot-free.
Allie Jamison could be considered this, particularly in Death Trap Mine. The fact she turned out to be right about Thurgood in the end (albeit not at all in the way she thought, and nothing to do with the main case they were investigating) didn't stop her smug attitude and Single-Issue Wonk from becoming irritating. May even have been invoked in-story when Jupiter says something deliberately geared to upset her just to get her to leave.
At least in the newer German releases, the boys do consider her to be this until much later on.
They Changed It, Now It Sucks: In Germany, two of the boys were renamed to "Justus Jonas" and "Peter Shaw" respectively. When they got the original names for some time, because of legal reasons, this trope happened.
They Wasted a Perfectly Good Character: In Kidnapped Whale, rather than the boys using Worthington and the Rolls-Royce to get around, the character of Pancho is suddenly introduced. He is a Mexican friend of the boys whom they kept out of jail when he was accused of stealing parts from the auto garage where he worked; in gratitude he's often available to take them places when Worthington, or Hans and Konrad, aren't. He's also extremely fascinated by cars in general, not only knowing all about them but capable of assembling new ones from the parts from various models, thus creating unique vehicles that people come from miles around to buy. Now whose background does this sound a great deal like, if we allow for some aging while keeping the trio the same? Carlos, from Stuttering Parrot. The way he is used as a substitute for Worthington is in itself a great idea that keeps the stories from being too repetitive and allows for traveling to different places, but considering Carlos had been fascinated by the Rolls himself, had befriended Worthington, and ended up working for the Rent 'n' Ride Auto Rental Agency, it wouldn't take much of a stretch to imagine he could have ended up owning his own garage in the future where his knowledge and ingenuity would allow him to assemble new cars from scratch. It would also neatly explain Carlos's missing Backstory, and the fact he was taking them in place of Worthington would have been the perfect opportunity to mention all this. Marc Brandel, the author of this particular book, also made an effort to include things from earlier in the series, like Jupiter's short-lived career as Baby Fatso, so it seems extremely odd he would not have taken this opportunity to do another Continuity Nod. Instead...this new character Pancho, and we never find out if Carlos and his uncle ended up with a brighter future.
Values Dissonance: Surprisingly and pleasantly avoided for the most part, other than the Yellow Peril Mr. Won from Green Ghost (and not only is his race not emphasized, he's balanced in the plot by the heroic Chang), the uptight and honor-obsessed Mr. Togati from Vanishing Treasure (who once he discovers he was wrong to dismiss the Investigators fully embraces them and thanks them for their help), and a few disparaging remarks about girls directed at Allie (to be expected from teenage boys). In fact while there are a few examples of old-fashioned views of certain ethnic groups which remain inoffensive, most of the time such things appear it is to disprove them, whether outright having such types be proven innocent after being suspected of villainy or having them and their culture actually validated and celebrated; Robert Arthur in particular had a fondness for this, seeing as he shows nothing but sympathy toward the Mexican boy Carlos, the Libyan Hamid, and the Greek Chris, and while he does indulge a bit in Roma stereotypes in both Terror Castle and Silver Spider, the first is a case of a movie actor from the silent film era who was deliberately invoking such things to scare the boys and the latter is forced to help by the villain and actually provides the keys to solving the mystery and saving the day. Talking Skull is even more about averting such views since the Roma are the heroes of the plot. William Arden follows the same path with the Yaquali of Laughing Shadow, carnies in Crooked Cat, and to some degree the Chinese in Dancing Devil, as does M.V. Carey with Wiccans in Magic Circle. However, much is made of the Mexican-American Alvaros' pride in Headless Horse, and the valorization of Cortes in the text is...rather uncomfortable.
Skeleton Island has a whole subplot with Chris Markos facing anti-immigrant prejudice and the trio opposing the townspeople who think he's a thief because he's a foreigner. Notably, the boys see the whole thing as idiocy from the get-go and reject such views, as does the town sheriff. The fact Arthur included such a plot and placed the reader's sympathies with the foreigner rather made him ahead of his time in a Values Resonance fashion.
On a related note, observe how Uncle Titus and Aunt Mathilda offer every assistance they can (including money) to the poverty-stricken Carlos and his uncle in Stuttering Parrot (as opposed to suggesting such 'parasites' go back to Mexico or commenting on their illegal status), and how when the Norrises are trying to drive the Alvaros out in Headless Horse, and Pico thinks they would have to go back to Mexico, the boys insist this would be wrong and that they are as much Americans as anyone else. Also, when they find out in Deadly Double that Jupiter got kidnapped helping the Nandans rescue Ian and prevent the native black people from being placed under a cruel, racist regime, Aunt Mathilda and Uncle Titus both pronounce Jupiter did the right thing and they're proud of him.
There is, however, the unfortunate example of Hoang Van Don, Hector Sebastian's Vietnamese cook. Although his errors in judgment when it comes to trying out new recipes, his misunderstanding of American culture and idioms, and his proclivity for learning via Pop-Cultural Osmosis result in some genuinely funny moments, overall there is a very uncomfortable sense of being made to laugh at the poor foreigner who just doesn't get the culture he's trying so desperately to fit into. The excessive use of Asian Speekee Engrish is also quite grating after a while.
Letitia Radford of Sinister Scarecrow. While she can be a bit annoying with her strident hysteria, she clearly is a harmless and mostly kind woman. Jupiter obviously has sympathy for her when he notices how haggard and upset she is, remembers Woolley telling them of all the broken engagements she's suffered, and observes that she is no longer young, but instead isolated and lonely. On top of that she has everyone dismissing her plight as her being crazy, and the Gaslighting itself is rather cruel, particularly when it's only to keep her from discovering a robbery being planned. The fact one of those responsible turns out to be someone she's known, trusted, and loved since she was a little girl is the heartbreaking icing on the cake; it's actually amazing and a sign of how truly good a person she is that she ends up forgiving the person.
Eleanor Hess of Wandering Cave Man, who is so badly mistreated by her nasty, mocking aunt and uncle that she is convinced she has no worth, is constantly clumsy and shy, and believes no one could ever love her or help her amount to anything. It's no wonder she decides to help one of the villains rob the McAfees and ransom the cave man so she can get the money she needs to escape their abuse, and it's extremely satisfying seeing her not only stand up to them in the end, but to get the home she deserves and turn it into a place for other lost, lonely girls to stay and get back on their feet.
Despite (or even because of) his eventual insanity, it's hard not to feel sorry for Luther Lomax in Rogues' Reunion, forgotten and ignored by everyone in Hollywood, having lost the chance to direct the adaptation of one of Hector Sebastian's books to a younger director, being forced to kowtow to the smarmy PR man Milton Glass, not even given a car by the studio until he begs for it (and points out it would make the studio look bad if they didn't).... The only real issue working against him, other than his insanity, is his arrogance toward the Wee Rogues(saying he hated directing them and making it clear he considered doing the show beneath his abilities) and in regards to his supposed great talent.