History Literature / TheThreeInvestigators

* OrwellianRetcon: After 1980, the conceit of having Creator/AlfredHitchcock introduce (through ghost writers) the books and interact with the boys was [[invoked]][[AuthorExistenceFailure no longer feasible]]. As a replacement, the authors created a mystery writer named "Hector Sebastian." Some editions of the earlier books written with Hitchcock as a character replace him with Sebastian (or the fictional director Reginald Clarke).

* TheElitesJumpShip: In ''The Blazing Cliffs'', unpopular businessman Charles Barron is convinced that society is on the verge collapse, and has withdrawn to a well-maintained self-sufficient ranch as he waits for his beliefs to be vindicated. A group of conmen fake a BenevolentAlienInvasion and offer to take Barron, his wife, and their valuables off-planet before an imminent war and then bring them back to Earth to be leaders of society once the war is over. Barron is prepared to follow their instructions (although, to be fair, he does think that his employees will be fairly safe back on the ranch, and many of them already think the whole thing is fishy) before being convinced that he's being conned.

* TheElitesJumpShip: In ''The Blazing Cliffs,'' wealthy ConspiracyTheorist and all-around {{Jerkass}} Charles Barron uses his fortune to finance the construction of a spaceship to help him (but not society as a whole) escape the planet before TheEndOfTheWorldAsWeKnowIt. The heroes show Barron that the world isn't about to end and that the people supposedly building his spaceship are con artists.

* WorthlessCurrency: One book has two men feuding over a lost safe belonging to a mutual ancestor who was a [[RunningTheBlockade blockade-runner]] during UsefulNotes/TheAmericanCivilWar. SurprisinglyRealisticOutcome when the money in the safe turns out to be Confederate paper money and is therefore worthless. However, the investigators realize the old wood the safe was enmeshed in could be sold to a specialty lumber mill for a tidy sum, which the clients agree to split.

** In ''Whispering Mummy'', the boys believe this must be how Ra-Orkon is being made to whisper, but it is pointed out right away that real ventriloquists can only "throw their voice" over very short distances, and there was no one else in the room except the professor. Despite this, suspicion falls on Wilkins the butler (because he once worked in vaudeville and thus could possibly have been a ventriloquist), as he's the only other person in the house even close enough to be a possibility. They also consider a radio for broadcasting, but none are found anywhere near the mummy. In the end it turns out to be case of ''literal'' voice-throwing: [[spoiler:Freeman, having knowledge of recording devices and a hobby in collecting various sound equipment, is able to use a special parabolic microphone to broadcast his voice, on a narrow line-of-sight radio signal across the canyon from his house to Yarborough's, so as to make the whispering happen wherever he wanted with pinpoint accuracy]].

* DyingClue: A few of the riddles or searches for lost treasure involve one of these. The Chumash Hoard's hiding place in ''Laughing Shadow'' is revealed by the last words of Chief Magnus Verde, while the delirious Joshua Cameron of ''Shrinking House'' babbled a message for [[spoiler:Marechal]] about the hiding place of the lost Fortunard. Don Sebastian Alvaro of ''Headless Horse'', dying in a cave after the American deserters hunted him down, left one on the wall next to him that was particularly cryptic, but inspired: "Ashes Dust Rain Ocean", meaning that like everything else in life, the Cortes Sword had gone back to where it began...

** Many riddles and puzzles in the series rely on these, but one of the best is ''Laughing Shadow'': the Chumash chief whose last words tell the location of the hoard said "it is in the eye of the sky where no man can find it". [[spoiler:It's hidden ''literally'' in an "eye of the sky", a cave inside a high mountain shaped like an Indian's head, with the cave inside the eye...and it is small enough no man can enter it, but a child or young teen can.]]

* PlotParallel: In ''Skeleton Island'', part of the local flavor for the area involves the legend of a pirate by the name of [[CaptainColorbeard Captain One-Ear]] who, when surrounded by British soldiers and on the verge of capture, ended up dumping his treasure down the blowhole (an aperture that shoots water during storms or when winds and waves are high) on the island known as the Hand, with [[FamousLastWords the taunting parting comment]] to his executioners that "Davy Jones had his treasure in his [[{{Pun}} grasp]] and would never let it go." Jupiter is able to solve the mystery of the book when he realizes the similarity to another local story the boys hear about, of an armored truck robbery in which the thieves, like Captain One-Ear, also supposedly dumped their loot overboard. Unlike the pirate, they were not merely assumed to have done so, but actually faked/mimed such a dumping so that the authorities wouldn't suspect they'd already hidden their money on Skeleton Island.

** Many riddles and puzzles in the series rely on these, but one of the best is ''Laughing Shadow'': the Chumash chief whose FamousLastWords tell the location of the hoard said "it is in the eye of the sky where no man can find it". [[spoiler:It's hidden ''literally'' in an "eye of the sky", a cave inside a high mountain shaped like an Indian's head, with the cave inside the eye...and it is small enough no man can enter it, but a child or young teen can.]]

* DyingClue: A few of the riddles or searches for lost treasure involve one of these. The Chumash Hoard's hiding place in ''Laughing Shadow'' is revealed by the FamousLastWords of Chief Magnus Verde, while the delirious Joshua Cameron of ''Shrinking House'' babbled a message for [[spoiler:Marechal]] about the hiding place of the lost Fortunard. Don Sebastian Alvaro of ''Headless Horse'', dying in a cave after the American deserters hunted him down, left one on the wall next to him that was particularly cryptic, but inspired: "Ashes Dust Rain Ocean", meaning that like everything else in life, the Cortes Sword had gone back to where it began...

** The German version has HandicappedBadass and [[TheSnarkKnight queen of snark]] [[TeenGenius Jelena]] with Jupiter. Her intelligence actually rivaling Jupiter's, one would have to be excused in thinking the [[SnarkToSnarkCombat snarkfest]] that occurs whenever they meet might be [[BelligerentSexualTension something else]]. [[DoesThisRemindYouOfAnything One could say]] [[{{Expy}} she's]] [[SherlockHolmes 'the woman']] for Jupe. She's also good friends with Bob; however their relationship is much more [[LikeBrotherAndSister amicable.]]

* WorthlessCurrency: One book has two men feuding over a lost safe belonging to a mutual ancestor who was a [[RunningTheBlockade blockade-runner]] during UsefulNotes/TheAmericanCivilWar. RealityEnsues when the money in the safe turns out to be Confederate paper money and is therefore worthless. However, the investigators realize the old wood the safe was enmeshed in could be sold to a specialty lumber mill for a tidy sum, which the clients agree to split.

* CathedralClimax: ''Silver Spider'' plays this one totally straight when the boys and Rudy are forced to take sanctuary in the Church of St. Dominic and climb one of the bell towers to escape the soldiers pursuing them--and because the circumstances involve ringing the bell of Prince Paul to encourage the people of Varania to rise up in revolution against [[EvilChancellor Duke Stefan]], [[TropesAreTools it's suitably dramatic and satisfying]].

* PowerTrio: Arguably the BeautyBrainsAndBrawn variation, with Jupiter as TheSmartGuy, Peter as TheBigGuy and Bob as the most sociable one. Though the Freudian model (Jupiter - Superego, Pete - Ego, Bob - Id) might cast an interesting light on tentative hidden sides of [[CovertPervert Bob Andrews]] (he ''does'' become a ChickMagnet in the modern relaunch of the series)...
** At least in the German audio adaptation Bob seems to alternate between TheCasanova and HandsomeLech with quite a bit of ChickMagnet thrown in. He even seems genuinely offended when a female client of theirs mistakes his bumbling effort at a distraction for [[CannotSpitItOut a bumbling declaration of love]] and [[HilarityEnsues actually turns him down.]]
** Also Peter has turned into a more traditional example of [[DumbMuscle the brawn]] being exeptionally gifted at [[NewPowersAsThePlotDemands whatever sport the plot requires him to]] while also being a [[TheDitz somewhat naive]] CowardlyLion due to a mix of {{Flanderization}} and CharacterizationMarchesOn. While this makes him very close to a BrainlessBeauty or DumbJock, he's saved by the fact that he's interestingly also the group's resident DeadpanSnarker.

* VehicularSabotage: Happens three times where the boys use it to stop a villain's pursuit or escape--in ''Shrinking House'' Bob removes the ignition wires from [=DeGroot=]'s car, in ''Dead Man's Riddle'' Billy takes the distributor cap off of Turk and Savo's car, and in ''Magic Circle'' Pete removes the ignition wires from every one of the villains' cars after they arrive at Madeline Bainbridge's estate. He doesn't count on one of them fleeing in Beefy's car however (which still had the key in the ignition). An unusual variation also occurs in ''Trail of Terror'', in which the boys sabotage a motorcycle belonging to a biker gang harassing them...so that when the gang goes to pursue them, its front wheel falls off.

* NothingIsScarier: A great deal of this appears in ''Phantom Lake'', surprisingly--the empty, ominous GhostTown of Powder Gulch; Mrs. Gunn, sitting alone in the lodge, listening to the sound of someone smashing stone in the night, until they all trek through the woods to find the collapsed smokehouse; the descent into the empty, shadowy quarry lit only by small bits of moonlight; and especially the visit to the fog-enshrouded Cabrillo Island, covered by the eerie twisted cypresses, knowing someone might be out there hidden in the mist...

* WorthlessCurrency: One book of has two men feuding over a lost safe belonging to a mutual ancestor who was a [[RunningTheBlockade blockade-runner]] during UsefulNotes/TheAmericanCivilWar. RealityEnsues when the money in the safe turns out to be Confederate paper money and is therefore worthless. However, the investigators realize the old wood the safe was enmeshed in could be sold to a specialty lumber mill for a tidy sum, which the clients agree to split.

** August August of ''Fiery Eye''. Gus reveals he was given the name by his father precisely because of when he was born and its relevance to the family name ("an August born in August can only be named August"); the boys at first think the letter from his Great-Uncle Horatio is using his name to tell them which bust the Fiery Eye is hidden in ("in August is your fortune" = "in ''Augustus'' is your fortune", i.e. either Augustus of Poland or Octavian/Caesar Augustus); and in the end the letter actually means that they can find the ruby's hiding place literally in the month of August, as [[CelestialDeadline the day and time of Gus's birth]] will show them where [[SundialWaypoint the shadow of the peak above Dial Canyon will fall]].

** Used to find the eponymous ''Fiery Eye''. Notable in that the waypoint is a mountain overlooking a canyon actually ''named'' (Sun)Dial Canyon.

** August August of ''Fiery Eye''.

* KarmaHoudini: Generally the series is not known for these--either the villain gets sent to jail at the end of the story, or if it's about pursuing a lost fortune/item, they fail to get it and leave at the end--otherwise unpunished for any fell deeds they committed while on the search, but failing to find what they coveted would be punishment enough in their eyes. At least twice though, a villain did actually escape despite the very real crimes they committed--Jensen, Mr. Won's minion in ''Green Ghost'', gets away (as does, for that matter, Mr. Won), while Rawley and his gang escape in ''Vanishing Treasure''. This last is notable not only because of the determined attempt by the boys that the "gnomes" of that case did ''not'' get to be this trope, but because of what Rawley did: he was an exceedingly clever criminal who almost got away with his loot, he coldly threatened Jupe and Pete with [[CementShoes being dumped off a ship with bags of silver coins tied to them]], and while he, like so many kids in the neighborhood growing up, had been one of Miss Agawam's gnomes and came to visit her frequently, he repays her as an adult by using the "gnomes" to frighten her into moving so she wouldn't discover the tunnel being dug under her house. Even though the "gnomes" do get caught, and Miss Agawam moves to a new home with no harm done, that's still a nasty thing to do to such a sweet, harmless person...and yet he still gets away.
* KickTheDog: While a number of villains do terrible things (for a kids' series version of terrible--as usual, none of them ever commit murder that we know of), two which stand out would be the villain of ''Laughing Shadow'' who indulges in child slave labor to find the treasure (and has every intention of either killing them or leaving them to die after he's gained the treasure so as to cover his tracks) and [[spoiler:Mrs. Chumley]] of ''Sinister Scarecrow'' who uses [[spoiler:her]] knowledge of Letitia Radford to create the terrorizing scarecrow; this last is one of the few things keeping [[spoiler:her]] from being a completely sympathetic villain.

* TheGuardsMustBeCrazy: While the example mentioned above under {{Foreshadowing}} in ''Silver Spider'' is played straight, in ''Singing Serpent'' the big bruiser who acts as a guard at the house in Torrente Canyon actually proves to be surprisingly smart: not only does he not fall for Jupe's lost cat story (when the alarms go off and Pete ends up falling over the wall), but after the boys learn the password to answer the phone at the gate so as to get inside the grounds, he is able to realize that it was opened one too many times when compared with how many members of the fellowship are in attendance. As Jupe says[[labelnote:*]][[WesternAnimation/TitanAE twenty-eight years before Preed]][[/labelnote]], "Very thorough. That man who tends the gate can count."

* GameBetweenHeirs: Variation. The eponymous ''Dead Man's Riddle'' does allow a competition between Dingo Towne's family members to find his hidden jewels, but because he hated most of them and distrusted or misjudged the rest, he also opened the game to any random person in town who could solve it.

** The early book ''Vanishing Treasure'' also makes use of the trope in a similar fashion, twice over: not only is Rawley's scheme with the gnomes meant to make Miss Agawam either so scared she moves away or locked up in an insane asylum for her nonsensical story, so that he is free to dig a tunnel under her house and [[TheConvenientStoreNextDoor rob the bank next door]], but he manages to rope her nephew Roger into the scheme by claiming he was hired to do this by the old theater's developer owner (who wants to but Miss Agawam's house as part of building his new high-rise office building); while Roger is not aware of the bank robbery aspect, he does go along with lying and pretending not to believe his aunt about the gnomes so that she will move out to an apartment as he wishes ([[EvilNephew so he'll have more to inherit, from her sale of the house]]). Like the above example, it's slightly subverted in that the gnomes reveal themselves to the boys, thus proving they aren't all in Miss Agawam's head--except at the point they do so, it's just to lure the boys into being captured long enough for the robbery to be pulled off, after which it won't matter if they tell anyone and are believed. Unlike the above example, the overall BigBad [[KarmaHoudini gets away with it]].

* {{Gaslighting}}: While the intent was only to distract her or force her to leave the estate so the museum robbery could go off as planned, the exploitation of Letitia Radford's fear of scarecrows and bugs in ''Sinister Scarecrow'' is malicious enough to count as this trope, and she nearly does go mad. Ends up being subverted, however, when the villains' concern that the boys will catch on to their scheme leads to the scarecrow attacking the boys, thus proving it isn't just in Letitia's head.

* ClueEvidenceAndASmokingGun: Quite often Jupiter uses this technique when confronting a criminal and exposing their guilt (or [[BluffingTheMurderer getting them to expose themselves]]), but a particularly textbook example (although one that is still played with a bit) occurs in ''Sinister Scarecrow'': when revealing [[spoiler:Mrs. Chumley]] as one of the villains, he begins by noting the odd discrepancies such as the suspect's knowledge of the crystal-hung candelabra on the Mosby Museum staircase landing or how they managed to get a box of heavy photographs down from a closet shelf [[spoiler:when she was supposedly unable to walk]], then moves on to their knowledge of Letitia's fear of bugs and scarecrows, the location of their room in the house, and their body size allowing them to be one of those wearing the scarecrow costume. The final piece of evidence, however? The strip of lighter wallpaper on the wall [[spoiler:around the frame of the Vermeer copy, proving it was the actual Vermeer since it was smaller than the copy, and there was no way she could have it unless she were in league with the Burroughs]]. The trope is played with in that the suspect angrily leaves the room before Jupiter can reveal the smoking gun, only to give away that [[spoiler:they can walk and]] they are indeed one of the villains when screaming and running out of the house [[ItMakesSenseInContext after finding army ants in their bed]]. The smoking gun isn't actually revealed until Jupiter is confronting a ''different'' villain [[spoiler:forger Gerhart Malz]], although it is still connected to the proof against them.

* ClearMyName: Doesn't happen very often at all, interestingly, but in ''Silver Spider'' the eponymous heirloom of Varania is planted in the Investigators' room to blame them for its theft as part of Duke Stefan's conspiracy, and the boys are genuinely in danger of being prosecuted or [[ColdBloodTorture worse]] for most of the book, or at least deportation and exile.

* ActionPrologue: Unusually, this occurs to some degree in ''Wandering Cave Man'', where Jupe encounters a strange pair of travelers in the fog near the junkyard, tries to help them get to where they're going...and then the male traveler has a heart attack and dies, requiring an ambulance be called. This is the first on-screen human death in the series, and it leaves an impression on the reader (and in-story, on Jupe). It's also a ChekhovsGun, for while at first it appears to have nothing to do with the story other than to introduce us to Eleanor Hess and the Spicer Foundation, it ends up being the work of Dr. Birkensteen (the man who died) that is at the heart of the case, since [[spoiler:he accidentally discovered a powerful, side-effect-free anesthetic in the course of his work, and it's this which the main villain uses to carry off his theft and ransom scheme via the town's water supply]]. Also, the beginning of ''Scar-Faced Beggar'' involves Bob's encounter with the eponymous character (who nearly gets hit by a car), then a brief ChaseScene, all while a bank robbery is going on (though this isn't learned by the characters until the next chapter). A few other books had this too, such as ''Stuttering Parrot'' (the first encounter with Claudius), ''Green Ghost'' (Bob and Pete's very atmospheric visit to Matthias Green's ruined mansion), ''Shrinking House'' (the pursuit of the figure in black from the cottage to the barranca), and ''Magic Circle'' (the boys being trapped in the fire at Amigos Press).