Grottoland (series)

Grottoland is a series of books by Pottypilot. It features two kids, Bob and Fiona, who are taken to an alien country called Grottoland. It currently has three books, the third of which has been left unfinished.

Books
The Grottoland series has three existing books.
 * 1) Grottoland (2015)
 * 2) * Two kids, Bob and Fiona, find a mysterious crystal in an underground cave and are kidnapped by aliens to another world. They must find their way home before a second alien race invades.
 * 3) Back to Grottoland (2016)
 * 4) * Upon returning from Earth, Bob and Fiona must rescue their parents from the heart of Grottoland.
 * 5) Army of the Future (2016)
 * 6) * The Grottolanders return to Earth to alert Bob and Fiona of a crazy, power-hungry general.