TY  - BOOK
AU  - Alice,Alex
TI  - Castle in the stars: the knights of mars 
T2  - Castle in the stars
SN  - 9781250206800 (hardcover)
U1  - GN FIC Castle #3 
N1  - 10-14
N2  - When Seraphin, Hans, and Sophie returned from their voyage to the moon, they didn’t come home empty-handed―they brought with them aetherite, a miraculous substance that defies gravity! To keep their secret safe from the Prussians, the trio lives in hiding on a remote island in Brittany. Meanwhile, Seraphin’s father has founded the International Society of Aether, a group of scientists dedicated to the peaceful pursuit of space exploration. But on the eve of their inaugural meeting, he vanishes without a trace!
The Knights of Aether’s last hope lies in a daring rescue of King Ludwig and Professor Dulac. They will find them on the farthest outskirts of the Prussian empire―the planet Mars!
ER  -