The Stone Gate, by Mark Mann, free
A strange rock in the forest. A mysterious crystal. A full moon. An ancient secret. How do you find your way home when you've never left?
Twins Jack and Kaya live in a small seaside town in Australia. When they see a dazzling white light shining from a giant rock in the forest near their home, it takes them on an adventure to a place both familiar and yet like nowhere they know. But where exactly are they? And can they find their way back in time?
The Stone Gate is a young adult fantasy adventure that explores global warming in a unique and exciting way.