If you thought the hot-air balloon scenes in Philip Pullman's His Dark Materials trilogy were exciting, hitch a ride on the Aurora airship in Kenneth Oppel's spectacular young-adult fantasy novel Airborn. Oppel, known for his best-selling Silverwing trilogy about the hidden lives of bats, has more in common with the famous British fantasy author than an interest in flight and a predilection for publishing books in threes. Like the popular Pullman series, Airborn is set in an alternative world where the similarities to our own are every bit as fascinating as the differences. In this case, what if some of the early 20th century's more bizarre experiments in aviation had actually worked? In Oppel's imaginary, not-so-distant past, giant luxury airships ply the air like ocean liners (thanks to a miraculous mango-scented gas called hydrium), while flying contraptions with feathered mechanical wings taxi people about--and everything else is slightly altered as a result.