Stargazer is the fifth book in the 'Land of Elyon' series by Patrick Carman

Patrick Carman

Patrick Carman is an American author of the The Land of Elyon series, the Atherton series, the Elliot's Park series, the Skeleton Creek Saga, and the fifth 39 Clues book. His books have been translated into approximately two dozen languages.-Biography:Patrick Carman was born on February 27, 1966,...

, taking place shortly after book 4 "Into the Mist

Into the Mist

Into the Mist is the prequel of the first book in The Land of Elyon series.-Summary:Before the walls went up... before the battle between Abaddon and Elyon... before Alexa Daley was born... there were two young brothers, Thomas and Roland Warvold, whose pasts were as mysterious as their futures...

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Plot

Alexa Daley, the protagonist, had only recently defeated the Abaddon (the main antagonist throughout the series)...or so she thought.
Abaddon was last seen falling back into the black pit in which he was contained, defeated along with Victor Grindall, one of Abaddon's underlings. Abaddon had taken on a new form, a metal serpent of the sea, harnessing the deadly power of electricity.