Carolyn, Tom, her uncle Hans with his trolls, her parents and many strange creatures suddenly find themselves caught up in a conflict between black and white magicians.

The witch queen wants revenge on those who once banished her from Earth.

So she launched a campaign against the inhabitants of the small continent of Mu, which she sank into the sea. But humanity is also under threat.

The friends, supported by Elisabeth and Betty, take up the fight, and once again science is on their side.

An exciting adventure unfolds.