These books by Kenneth Oppel are amazing! Here's a brief summary of what happens in each book...
Spoiler:
Matt Cruse is the 15-year-old cabin boy aboard the Aurora, the 900-foot luxury airship he has called home for the past two years. While crossing the Pacificus, Matt fearlessly rescues the unconscious pilot of a crippled hot air balloon. Before he dies, the balloonist tells him about the fantastic, impossible creatures he has seen flying through the clouds. Matt dismisses the story as the ravings of a dying man, but when Kate de Vries arrives on the Aurora a year later, determined to prove the story is true, Matt finds himself caught up in her quest. Then one night, over the middle of the ocean, deadly air pirates board the Aurora. Far from any hope of rescue, Kate and Matt are flung into adventures beyond all imagining. . .
Spoiler:
At 20,000 feet drifts a legendary ghostship...
The Control Car of the giant airship is almost entirely encased in ice, the ship’s name barely visible on her tattered skin: Hyperion. Matt Cruse can’t believe his eyes. Can this really be the legendary lost craft, now a frozen mausoleum to a ghostly crew and a vast treasure? At 20,000 feet, aboard a decrepit training ship, Matt is almost unconscious from the high altitude, but of all the oxygen-starved crew, he alone remembers the Hyperion’s coordinates.
Back in Paris, it suddenly seems that everyone is after those coordinates. Kate de Vries, Matt’s rich, young lady friend, has her reasons. But what about the handsome captain, who’s going to pilot them back to the Hyperion? Or the mysterious gypsy girl, whose past is inextricably linked to Matt’s?
In an adventure that will test his courage, his skill, and his heart, Matt is about to take off on the ride of his life.
Please read these books, you will hang on to every word! There is the third book coming out called Starclimber probably this year, too.