History Literature / TheHardyBoys

** Chet Morton also gets several across the books, such as Salamaji in "The Search for the Snow Leopard" and Jerri in "Trouble in Warp Space" (both Digests), Dawn in "Cold Sweat" from the ''Casefiles'', and Liz in "Martial Law" from ''Undercover Brothers''.

*** "Beyond the Law" delves into Chief Ezra Collig's backstory and reveals that, when he was a rookie officer, he was paired up with one of the best cops on the force, Ray Boseman, whom he greatly admired...until he learned that Boseman was running a racketeering scheme to collect money from local shopkeepers in exchange for protection. Collig reported him, and Boseman could never hold down a job for long before he turned to crime again, eventually going over to the other side completely and then eventually being put in prison. He returns in the present to pull a FrameUp on Collig in revenge.

** Three different supporting characters who are current or former cops have/had a partner on the force who went corrupt:

*** In the first Supermysteries series, Frank and Nancy share a mutual attraction, but rarely act on it due to their commitments to their respective partners. Joe and Bess have one as well, but how strong it is and how they act on it varies widely between books.
*** In the second Super Mysteries, Frank definitely has a crush on Nancy, but it's unrequited due to her only having eyes for Ned (though she sometimes does flirt with Frank a little). Joe is also interested in her in the first book, but mostly goes for Bess in subsequent volumes (possibly since he knows Frank likes Nancy), though it never actually goes anywhere.

** In ''Undercover Brothers'', Chet is the ''only'' male friend of theirs from the original books who still appears; all the others are never name-dropped even once. Callie here as well; she makes one appearance in an earlier book of the former series before dropping out. Even Iola, who still appears, is no longer Joe's girlfriend; she's simply a friend of both brothers, as is Callie.

** In ''Undercover Brothers'' and ''Adventures'', Chet is the ''only'' male friend of theirs from the original books who still appears; all the others are never name-dropped even once. Callie here as well; she makes one appearance in an earlier book of the former series before dropping out, and hasn't yet appeared at all in the latter series. Even Iola, who still appears, is no longer Joe's girlfriend; she's simply a friend of both brothers, as was Callie for her sole ''UB'' appearance.

** Standard fare in the second half of the ''Undercover Brothers'' stories, which consist of three-book stories that have multiple mysteries involving the same characters. Frank and Joe will catch someone who confesses to some of the activity, but denies being responsible for something else, and are soon proven to be telling the truth by a fresh act of sabotage or threatening message.

** Standard fare in the second half of the “Undercover Brothers” stories, which consist of three-book stories that have multiple mysteries involving the same characters. Frank and Joe will catch someone who confesses to some of the activity, but denies being responsible for something else, and are soon proven to be telling the truth by a fresh act of sabotage or threatening message.

*** This time, Frank probably gets it worse, as his nerdiness gets emphasized more and more to the extent that he and Joe practically become polar opposites. At one point, Frank states that his favorite movie from a previous year was a ''documentary about ladybugs''. Probably the most egregious example is that, in "Comic Con Artist" (book #21), both Joe and Frank are shown and stated to be comic book fans and are excited to immerse themselves in a [=ComicCon=] scene, but then in the Deathstalker Trilogy (books #37-39), Frank acts like comic books are for little kids, states that he stopped reading them a long time ago and now prefers a "higher class" of literature, and scoffs at Joe for still being a fan.

*** Thankfully, the ''Undercover Brothers'' graphic novels series averts this, keeping both boys' characters fairly intact throughout.

* GuileHero: Especially in the ''Casefiles'' books when they are almost always have to fend for themselves to outwit their enemies. Frank in particular can be a very efficient [[TheChessmaster chessmaster]], but even Joe can pull a few tricks of his own.

*** Aunt Gertrude Hardy in "A Killing in the Market", where she briefly gets a LoveInterest who is later murdered, and she's accused of killing him.

* ScrewTheRulesTheyreNotReal: In one book of the ''Casefiles'' series, the chief of police warns the brothers that TheMafiya doesn't adhere to anything like the codes of honor that homegrown organized crime gangs often do, because a stay in an American jail is comparatively lenient next to what would happen to them in their home countries.

* TheTeam / TrueCompanions: The Hardy Boys and their friends in the Digests and ''Casefiles'':
** [[TheLeader The Leaders]]/[[TheHero The Heroes]]: Frank and Joe Hardy
** TheLancer: Chet Morton
** TheSmartGuy: Phil Cohen, and often Frank as well
** TheBigGuy: Biff Hooper (of the GentleGiant variety), and often Joe as well
** TheEveryman: Tony Prito
** TheChick: Callie Shaw, plus Iola Morton (Digests) / Vanessa Bender (latter half of the ''Casefiles'')
* TeenGenius: Frank, who has a disturbingly deep knowledge of things like investigative technique, criminal profiling, and computer hacking for an eighteen-year old.

*** Just compare the two trilogy stories from each series: the ''Casefiles'' has "Operation Phoenix" (involving a smuggling ring and the brothers believing their father to have been murdered) and "Ring of Evil" (in which the boys literally save the world from terrorists), while Nancy's "Summer of Love" and "Passport to Romance" trilogies, though still containing dangerous mysteries for her to solve, have her relationships with handsome studs she meets during the summer as their overarching storylines.
*** It's also reflected in the cover illustrations for both series. The ''Casefiles'' covers depict a frightening and/or action-filled scene that occurs during the book, and while many of these pictures do have one of the Hardys protectively clinging to a beautiful girl (sometimes Callie, sometimes the GirlOfTheWeek--which, it should be noted, also happens many times on Digest covers), it's always in the context of one of these scenes, with the characters looking shocked or scared. Contrast this with the ''Files'', where many of the books do likewise depict an action scene on the front, but plenty of the earliest and latest covers show an illustration of Nancy and the most important male character in the book (often Ned), often with said guy giving her an intent, admiring gaze.

** Frank's and Callie's relationship gets significantly more focus than in the Digests, portraying a deeper bond and giving them many more moments that show how much they love each other. Though Iola is killed at the start of the first book, various characters reminiscing about her and Joe's relationship also highlights the deep love they shared in a way the Digests don't. The ''Casefiles'' also references many instances of characters sharing makeout sessions (whereas the Digests don't go further than a "quick kiss"), and tends to highlight both brothers' feelings and emotions towards their LoveInterests more. There are also quite a few more instances of other girls or guys hitting on the brothers or their girlfriends and causing relationship drama, whereas in the Digests, on the very few occasions that someone else showed interest in the boys or their dates, they didn't take it very seriously and it didn't have any real effect on the plot.

** Frank's and Callie's relationship gets significantly more focus than in the Digests, portraying a deeper bond and giving them many more moments that show how much they love each other. Though Iola is killed at the start of the first book, various characters reminiscing about her and Joe's relationship also highlights the deep love they shared in a way the Digests don't. The ''Casefiles'' also references many instances of characters sharing makeout sessions (whereas the Digests don't go further than a "quick kiss"), and tends to highlight both brothers' feelings and emotions towards their LoveInterests more.

** However, it should be noted that this is still quite {{Downplayed|Trope}} compared to its ''Nancy Drew Files'' counterpart series, where romance is much more strongly emphasized and its own DarkerAndEdgier aspects are conversely downplayed compared to the ''Casefiles''. Just compare the two trilogy stories from each series: the ''Casefiles'' has "Operation Phoenix" (involving a smuggling ring and the brothers believing their father to have been murdered) and "Ring of Evil" (in which the boys literally save the world from terrorists), while Nancy's "Summer of Love" and "Passport to Romance" trilogies, though still containing dangerous mysteries for her to solve, have her relationships with handsome studs she meets during the summer as their overarching storylines.

** In "Hits and Misses", one of the [=SuperMysteries=] Nancy Drew, the sleuths meet a woman with memory loss who goes by the standard "Jane Doe" until they can help her remember her identity. Funny enough, her actual name really ''does'' turn out to be Jane [Orbach].
** In a book from the second Super Mystery crossover series, "Danger Overseas", they meet a fellow teen who had such a bad FreakOut that she got TraumaInducedAmnesia from it, including her name. She initially chooses to go by "Lily" because she likes the sound of it, but they soon realize that she is Caitlin, a recently-arrested-suspect's missing girlfriend whom they were searching for, and even before she remembers everything else, does recall that this is indeed her name.

** The ''Casefiles'' series. Iola Morton is Joe's long-running girlfriend in the original series, and gets blown up by terrorists seconds before the opening scene of ''the first book''. Not to mention that some cases would place tension between the brothers, which would often lead into not-so-friendly brawls between them. Later, it also modifies their relationship with the police (which is scarcely a problem in the original series), with an AscendedExtra of sorts in Con Riley as the only officer that takes their skills seriously. They also use guns, and bad guys regularly try to JustShootHim. And then there are the Assassins, the terrorist group responsible for Iola's aforementioned murder, and are also the most frequently recurring villains in the series who, well...[[ExactlyWhatItSaysOnTheTin do exactly what you might expect]].

* HotterAndSexier: The ''Casefiles'' spin-off, which was targeted for older teenage readers than the concurrently-running Digests, were this compared to all the other series in the franchise.
** Frank's and Callie's relationship gets significantly more focus than in the Digests, portraying a deeper relationship and giving them many more moments that show how much they love each other. Though Iola is killed at the start of the first book, various characters reminiscing about their relationship also highlights the deep love between them in a way the Digests don't. The ''Casefiles'' also references many instances of characters sharing makeout sessions, and tends to highlight both brothers' feelings and emotions towards their LoveInterests more.
** However, it should be noted that this is still quite {{Downplayed|Trope}} compared to its ''Nancy Drew Files'' counterpart series, where romance was much more strongly emphasized and its own DarkerAndEdgier aspects were likewise downplayed compared to the ''Casefiles''. Just compare the two trilogy stories from each series: the ''Casefiles'' has "Operation Phoenix" (involving a smuggling ring and the boys believing their father to have been murdered) and "Ring of Evil" (in which the boys literally save the world from terrorists), while Nancy's "Summer of Love" and "Passport to Romance" trilogies, though still containing dangerous mysteries for her to solve, have her relationships with handsome studs she meets during the summer as their overarching storylines.

After the books were acquired by Simon & Schuster (which took control of Grosset & Dunlap in the 70s after a lawsuit), the series was continued as "Digests". Later on, the DarkerAndEdgier ''Casefiles'' series was added and ran concurrently with the Digests. Both series have since been discontinued, the ''Casefiles'' in 1998 and the Digests in 2005. The series has since continued under the ''Undercover Brothers'' subtitle, which reinvents the brothers as agents working for an all-teen secret agency; there is also a corresponding graphic novel series. It was discontinued in 2012 after 42 books[[note]]39 regular volumes and 3 special edition "Super Mysteries"[[/note]] and 20 graphic novels. One year later in 2013, it was replaced with the currently-running ''Hardy Boys Adventures'' series (with 20 volumes published as of this writing), which sees the boys return to amateur detective status.

* AnswerCut: In "The Borgia Dagger" from the Casefiles series, after RichIdiotWithNoDayJob Tessa Carpenter loses most of her money, the brothers reflect on how she has to get a job now, but wonder what she'd possibly be skilled enough to do. Then they happen to walk past a TV showing a soap opera and take a look at the actress playing an over-dramatic rich girl...

** 2017-Present: ''Adventures'' reduced to bi-annually.