The Peter and the Starcatchers saga, written by Dave Barry and Ridley Pearson, is a series of fantasy novels; starting out as prequels to Sir J.M Barrie's Peter Pan, but gradually deviating from its plot. The series contains four books:
Peter and the Starcatchers
Peter and the Shadow Thieves
Peter and the Secret of Rundoon
Peter and the Sword of Mercy
A new series in the same universe of Peter and the Starcatchers begins with the book The Bridge to Neverland.
This series provides examples of:
Action Prologue: Sword of Mercy opens with a battle between Charlemagne and Ogier the Dane. Receives a Call Back at the end of the novel with one between Peter and Hook.
Just Between You and Me: This happens pretty much every time The Others capture one of the good guys. In the third book, Ombra admits he just wants to see Leonard's reaction once he knows what's really going on.
Trilogy Creep: Originally the book started as a trilogy, and then came Sword of Mercy, acting as a full fledged prequel to the events of Peter Pan.
Two Part Trilogy: The first work can actually stand by itself, acting as an introduction with the major plot points (of that book) more or less resolved. Around Shadow Thieves, the series starts to blend together into a bigger story arc.
The Watson: Peter. There's a whole chapter where Molly goes on a Character Filibuster to tell him all about Starstuff and the history of the Starcatchers, and another bit where Fighting Prawn explains Mr. Grin's origin story to him.
You Said You Would Let Them Go: In the third book, after Peter locates the starstuff. Zarboff decides to feed the boys to the snake anyway—he only promised that if Peter didn't do as he was instructed, he would feed them to the snake. He didn't say anything about not feeding them to the snake if he did follow the instructions.