The six books of Anne [=McCaffrey=] and Elizabeth Ann Scarborough's ''Petaybee'' series are divided into two trilogies: ''Petaybee'' and ''The Twins of Petaybee''. The protagonist of the first is Yanaba "Yana" Maddock, a soldier sent to the planet of Petaybee when injuries from a terrorist attack make it impossible for her to continue in the army. In the second trilogy, the central characters are Yana's children, Ronan Born for Water and Murel Monster Slayer Maddock-Shongili.

In all six books, the plot is basically the same: the planet must be protected from Intergal, an interplanetary company that wishes to relocate the inhabitants so it can mine for valuable minerals.

The series is not nearly as well known as the [=McCaffrey=] DragonridersOfPern books, but is often considered to be of greater quality, as a whole.

Books in this series:

* ''Powers That Be'' (1993)
* ''Power Lines'' (1994)
* ''Power Play'' (1995)
* ''Changelings'' (2005)
* ''Maelstrom'' (2006)
* ''Deluge'' (2008)

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!!This series contains examples of:

* ActionMom: Yana
* BadassNormal: Yana
* BigBad: Intergal
* CatsAreMean: played with
* ChildrenAreInnocent: 'Cita, oddly
* CultureClash: the cult that raised 'Cita and the rest of Petaybee
* FailOSuckyName: The cult that raised 'Cita gave all of its girls humiliating names, until they "came of age." (Read: became old enough to join the leader's harem). 'Cita's name was "Goat-Dung."
* GeneticEngineeringIsTheNewNuke: the Shongilis
* GuineaPigFamily: the Shongilis
* KindheartedCatLover: Clodagh
* LighterAndFluffier: ''The Twins of Petaybee''
* LongLostSibling: Bunny and [[spoiler: her younger sister, 'Cita.]]
* MamaBear: Yana
* MegaCorp: Intergal
* MenaceDecay: Dr. Luzon and Intergal
* PowersThatBe: Intergal again
* PrecociousCrush: a particularly disturbing example
* RaisedByWolves: 'Cita
* RuleOfDrama: a staple of [=McCaffrey=]'s work
* SecondLove: Sean to Yana.
* SelkiesAndWereseals: The series employs the selkie myth in a futuristic setting. The Shongili family uses genetic engineering to create a selkie (Sean). Sean's kids are natural-born selkies as well.
** There's a hint from Sean that his grandmother was a selkie. He says she "taught him how to swim", with a significant wink at Yana.
* SpinOffspring: Murel and Ronan's series
* TakeOverTheWorld: rare justified example
* TouchedByVorlons: Petaybee changes those who live on it
** BlessedWithSuck: And past a certain age (early adulthood), those changes mean painful death for anyone who's off-planet for as little as a couple of days.
* UntoUsASonAndDaughterAreBorn: Murel and Ronan
* VillainWithGoodPublicity: the Intergal corporation
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