YMMV / Three Can Keep a Secret

• Accidental Aesop: The first story of the project has something along the lines of "You shouldn't feel obligated to preserve, cherish, or honor the circumstances of a childhood that hurt you. Wanting to decide, define, and even redefine your own position on these circumstances on your own terms and pace is perfectly valid."
• Alternate Character Interpretation:
  • Was Priscilla actually dating other men, or was that Preston's paranoia? If she was, was she doing it because she was greedy and wanted other men's money and prestige now that she couldn't use Preston's, or because Preston couldn't be counted on for safety and financial support any longer? The building Preston bought to house their family was dilapidated and despite their still-substantial fortune he only paid to repair the portion of it he himself used, implying he didn't bother to fund basic necessities for the rest of the family. While there's no question Priscilla's self-centered and that she utterly failed her daughter by choosing to leave her with Preston for extended periods of time, Preston's severe neglect of his family's needs and increasingly physically abusive behavior is certainly enough of a motivation for Priscilla to try to leave him even without greed involved. And Preston proves he wasn't safe for Priscilla to be around when he kills her.
  • When trying to ward off Bill's presence, an increasingly insane Preston kills his wife Priscilla to use her as an offering to save his own skin, but plans to take Pacifica with him when he flees, intending for them to become serial killers together. Is the fact that he doesn't consider killing or abandoning Pacifica evidence of at least some kind of parental feeling, however small and twisted, or does he just consider her more useful to him alive?
• Base-Breaking Character:
  • Mabel is of course the main source for this, as per the source show, with some reviewers seeing the fic as a refreshing and well deserved addressing of her flaws and the consequences of her actions that is never the less still trying to build her up into a likable, more mature character, or that the in-depth exploration of Mabel's flaws beyond merely being selfish and the continued challenging of her values to demonstrate her complex motivations makes her more interesting, relatable, and sympathetic than she was in the show despite this version of Mabel continuing to make similar mistakes. Others say the fic maliciously mischaracterizes Mabel purely due to the author's dislike for her, unfairly ramping up her existing flaws while outright ignoring all her development and that the above mentioned attempt at character development is just a mean spirited Trauma Conga Line.
  • To a lesser extent, this fic's Dipper also proves divisive: Some view him as a cool, mature Science Hero with an intriguing moral ambiguity to his actions and whose relationship with Pacifica is adorable, while others view him as an amoral Jerkass whose more ruthless actions are glossed over and who should be dating Wendy instead.
• Complete Monster: Bill Cipher retains his canon crimes and adds to them. Using a spell to come Back from the Dead at the cost of dividing himself into nine weaker pieces, all of which have his personality in full, two of the Bill fragments attempt to kill the Pines family, taunting them with the knowledge of Mabel's deal with him and the knowledge that they intend to destroy the Earth. Another Bill fragment takes over an alien scientist and attempts to destroy all life on multiple planets; jumps to a gas harvesting foreman and attempts to blow up the facility, killing everyone on board and poisoning the environment; and attempts to drain the life force of everyone in a hospital. A fourth fragment works to engineer a massive war in Mewni, selling improperly stored weapons to monsters and playing politics, with a bit of terrorism added in, to force other factions into the war. Wanting nothing more than to cause as much death as possible, Bill constantly proves himself to be pure evil.
• Diagnosed by the Audience: The story treats Mabel's moments of instability in the show completely seriously, so there's a very good case to be made that this characterization of Mabel has some sort of personality disorder.
  • She shows little awareness for others' boundaries, is extremely impulsive to the point of sabotaging her own goals without thinking, and is very charming despite her inflated sense of her own importance (and, contradictingly, frequent self-loathing).
  • While she demonstrates a capacity for empathy in her instantaneous support for shielding Pacifica from her father, Mabel struggles intensely throughout the story with feeling, processing, and expressing it, to the point of damaging her relationship with her brother due to her inability to give back emotionally in the way he needs.
  • She suffers from erratic and frequently shifting emotions sometimes manifesting in sudden and intense aggression, especially as she moved into adolescence; at one point she gets so jealous she briefly contemplates killing Pacifica for daring to be closer to Dipper than Mabel herself is now, a sudden shift which even startles Mabel herself but which she still struggles to restrain.
  • She's extremely parasitic in her relationship with her brother with no idea, initially, why this behavior is wrong, and without him to keep her on track during the years he lived in Gravity Falls, she was unable to manage the demands of school, struggled to meet, manage, or even make realistic long-term goals for herself, and became, according to Word of God, a "pretty hardcore" juvenile delinquent.
  • She has a long history of failing to learn from repetitive mistakes, self-delusion, denial, and many short-lived yet very intense romantic (and possibly sexual) attachments.
  • It's implied that, pre-Character Development, a lot of her inability to accept Dipper's desire to live separately was because he helped to compensate for her difficulties functioning in the world.
  • It's worth noting that Mabel also has the interpersonal history often associated with such disorders, having lived through both a bad home environment and extreme trauma, both issues for which she actually received less support as she got older owing to her increased coinciding inability to confide in her companions in Piedmont and resistance to confiding in those who actually went through the traumatic experience with her.
  • After she and Dipper have their falling out, she displays a repeat of her very concerning canonical behavior of self-harming emotional incapacity, which is also treated completely seriously.
• Harsher in Hindsight: Mabel’s extremely jealous and possessive reaction to Dipper and Pacifica bonding in this fic is really uncomfortably similar to the Awful Truth behind Emperor Belos, despite having been written years before the truth behind Belos came out.
• Hilarious in Hindsight:
  • Irony with a bit of Fridge Brilliance: The planned ending involved the Pines family basically becoming Household Names for their inventions, contributions to science, and guiding influence during Earth's transition from an isolated and mostly nonmagical world to an important dimension in Multiversal politics—and as both the family's CEO and most politically astute member, Pacifica would obviously be one of the most influential and historically important Pines. This means that, in the long run of this AU, the Northwest family's historical legacy is probably defined by the one Northwest that most wanted to sever ties from the rest, and for all the pride the Northwests had in their fake history and how much Preston accused Pacifica of sullying the family name, one could easily imagine the Northwest Mansion someday becoming a registered historical site mostly because it's Pacifica Pines' childhood home.
  • The story’s use of Emperor Belos as the Token Evil Teammate of the Pines-Butterfly Coalition has its own irony to it now that his actual nature has been revealed in canon. He is *also* a magic studying, dimension traveling human Knight Templar who justifies his actions with the protection of earth and humanity. Until we find out that even that's not the whole story... because his motivations parallel Mabel.
  • While it has awful implications for her character, it's hilariously absurd on a meta level that the Harsher in Hindsight reveal above is the second time Mabel's characterization in the first story has closely paralleled an antagonist from The Owl House, despite that story having been completed the year before The Owl House began airing.
• Jerkass Woobie: Mabel's been through significant trauma and received the least amount of support for it because she refused to be honest about what happened with the people who could've understood for fear that they would hate her. She's self-serving and callous but it comes from trauma, fear, and a childhood that left her with unhealthy expectations for her place in the world. And what she's wanted most these past three years is simply for her brother to be at her side and help her through everything.
• Misaimed Fandom: A decent portion of commenters agreed with Mabel's accusations that Pacifica is a bad influence on Dipper and hate the fact that the other characters treat Mabel like her behavior is the bigger problem, despite the fact that the author states the purpose of the story is to deconstruct Mabel's Aesop Amnesia through a Karma Houdini Warranty, that Mabel's clearly projecting much of her manipulative behavior towards Dipper onto Pacifica, and that Pacifica is pretty explicitly written as Mabel's Foil by being more self-aware of their similar flaws and seriously trying to overcome them instead of denying them. In fact, Pacifica's greatest fear in the story is returning to the self-centered person she was raised to be and somehow benefiting from manipulating Dipper, in contrast with Mabel, whose explicit intention for most of the story is to manipulate Dipper back into a relationship dynamic she prefers better.
• Tearjerker: Depending on how the reader feels about Mabel, it can be genuinely heartbreaking to read Part 1 of the project, Three Can Keep A Secret, owing to just how out of control Mabel's mental state has become in the last three years. She went home from Gravity Falls when she was thirteen and felt she couldn't tell anyone there what she'd been through. Losing Dipper as her Cloudcuckoolander's Minder at the same time as losing her ability to emotionally confide in others about things that upset her basically left her to try to function with her unhealthy worldview and trauma alone. It didn't go well. While the audience has had varied reactions regarding whether this is a believable direction for the character, for those who do believe it, the juxtaposition between the perpetually Cheerful Child Mabel was at twelve and the resulting unstable and mentally disordered Delinquent she is a fifteen, and the emotional journey she has to go through to process and heal from everything she'd been suppressing and denying during that time, can be almost as emotionally challenging for the reader as it is for her.
  • A particularly tragic part is when—under the weight of Mabel's fears and main coping mechanism, denial—Mabel begins the story seeking out scapegoats for her problems, and immediately selects Pacifica because of Pacifica's close relationship with Dipper. Pacifica is someone whose friendship had been hard-won by both Pines twins the previous time Mabel was in town, but under the weight of all the built-up tensions, it just crumbles. They eventually manage to get along for Dipper's sake, but so far, that's about it.
• They Wasted a Perfectly Good Character:
  • Considering her status as a Cool Big Sis to Mabel in the show, Wendy would have been in a great position to help Mabel with her issues. It's a shame she ended up sidelined to bit character status. Alternatively, given Wendy's past enabling of how Thompson was treated, her insistence that Mabel is a "straight up saint," and her reinforcement of the twins' co-dependence by telling Dipper his priority should be Mabel because he and Mabel need each other to succeed (at Dipper's lowest and most vulnerable moment in Weirdmageddon during which it was unknown whether Mabel was even alive or dead, no less!), having Wendy around could have been a great opportunity to explore the social peer influence aspect of Mabel's denial (as part of Mabel's difficulty with changing is that no one who loves her has actually expected her to be better, which Wendy enables at several points in the show). Also, if Wendy's begun to grow out of some of her issues, she could have been a model for Mabel when it comes to facing mistakes and managing relationships with people she's hurt in the past—using Wendy's friendship with poor Thompson as an example.
    • Wendy was planned to make a reappearance in the canceled third story, during which she does spend a significant amount of time with Mabel, and the changes in Wendy help Mabel further come to terms with the inevitability of change.
  • Given the increasing involvement of The Owl House in the episodic outline, one wonders why Mabel's development against selfishness relies so heavily on the encounter of Gideon as a negative example and yet never connects Mabel with a negative example far more like herself, Lilith Clawthorne. Like Mabel, Lilith is an older sister who selfishly sabotaged her younger sibling's future prospects for her own desires and never willingly owned up to it, even years later. Also like Mabel, even now that she's lived for years with guilt, Lilith still thinks she's the one to decide the correct way for all the problems in her sibling's life to be solved, even if said sibling staunchly disagrees. Lilith's selfish mistake, coverup, and controlling behavior deeply harms her sister's life and their relationship to this day. All of this means that there are a lot of parallels between her and pre-development Mabel.
    • Ascended. In the fic's planned equivalent of "Agony of a Witch," Mabel calls out Lilith on her behavior, explaining that if Lilith took control of Eda's life, even if only to "help" her, then Lilith wouldn't have a sister, she'd have a prisoner. This moment gives Mabel a Heel Realization on Dipper's capacity for forgiveness.
• The Woobie:
  • Pacifica, for her Abusive Parents, dramatic change in living standards, and the fact that her faith in her new friend Mabel—someone who helped her change so much of who she is—was destroyed after she learned how badly Mabel treated her brother.
  • Dipper, for being The Unfavorite to his parents and in a toxic All Take and No Give relationship with his sister; the only way to escape it was basically to dissolve his relationship with his sister for a time, which clearly hurts him deeply.