* AlternativeCharacterInterpretation: Again Heather. Is she really just a spiteful, manipulative brat or is she an emotionally damaged girl desperate for the attention and approval of her family and peers. Sammy can't seem to figure her out.
** Sammy can be viewed as either a plucky amateur sleuth, or a nosy girl who causes trouble for all her friends.
* DracoInLeatherPants: Heather seems to have shades of this for most fans, especially in later books.
* GrowingTheBeard: The series was good to begin with, but as time has gone on, the books have combined episodic mystery with arc-based character drama, thoroughly averting StatusQuoIsGod.
* NightmareFuel: ''Sammy Keyes and the Hollywood Mummy''. And in ''Dead Giveaway'', it turns out that [[spoiler:the abusive husband has been dead for a while, and his wife has been posing as him and hiding his body in her compost pile.]]
* StoicWoobie: Good Lord, Holly. Her parents are dead, she's lived in eight abusive foster homes, and when Sammy finds her, she's living in a cardboard refrigerator box down by the river.
* ToyShip: Sammy/Casey. Marissa/Danny is ''not'' a BetaCouple, since they have roughly the same amount of trouble getting together.
* TrueArtIsIncomprehensible: Mocked thoroughly in ''Art of Deception''.