
Acorna
science fantasy
Series · science fiction
The Petaybee series by Anne McCaffrey has 6 books and is best read in publication order, starting with Powers That Be (1993).
Start here: Powers That Be (1993) — then read straight through in publication order.

The order the books were released — the default way to read the series.
Petaybee is an out-of-the-way colony world that a mining conglomerate wants to strip for resources, dismissing local reports that the planet itself is somehow sentient and actively protecting its human and animal inhabitants as colonist superstition. Anne McCaffrey and Elizabeth Ann Scarborough's Powers That Be (1993) opens the trilogy through Yanaba Maddock, a career military officer sent to Petaybee to retire quietly who instead finds herself defending a planet that seems to be alive, intelligent, and capable of reshaping its own geography to protect the people it has decided are its own. Power Lines and Power Play widen the conflict into a fight to keep the corporation and a hostile off-world government from exploiting or destroying what Petaybee actually is.
A decade later, McCaffrey and Scarborough returned to the planet with the Twins of Petaybee trilogy — Changelings (2005), Maelstrom (2006), Deluge (2008) — following the next generation of Petaybee's human-animal shapeshifting descendants as the planet's sentience and its people's changing abilities become central to the story rather than a mystery to be solved. Across all six books, the series treats an entire planet as a character with its own agency, a recurring McCaffrey interest also visible in Pern's living, telepathic dragons.
Read the original Powers trilogy first, in publication order: Powers That Be (1993), Power Lines (1994), Power Play (1995). This establishes Petaybee's sentience and the political fight to protect it, and ends the initial conflict. The Twins of Petaybee trilogy — Changelings (2005), Maelstrom (2006), Deluge (2008) — picks up a generation later following the original characters' shapeshifting descendants; it assumes you already know how Petaybee works, so reading the Powers trilogy first is strongly recommended even though the two trilogies were published a decade apart.
Start with the Powers trilogy in publication order — Powers That Be (1993), Power Lines (1994), Power Play (1995) — then continue with the Twins of Petaybee trilogy: Changelings (2005), Maelstrom (2006), Deluge (2008).
All six books are co-written by Anne McCaffrey and Elizabeth Ann Scarborough.
It's a direct continuation, set a generation after the original Powers trilogy and following the descendants of that trilogy's characters on the same sentient planet.
Six: the three-book Powers trilogy (1993-1995) and the three-book Twins of Petaybee trilogy (2005-2008).
No, it's a self-contained universe unrelated to Pern, the Talents Universe, Acorna or her other series.
Reading order last verified .