The villains have followed the Cassidy girls to Australia.

Although the Australian police have relocated the girls to a safe house in Sydney, Emma may have revealed their new location by mailing a birthday card to Sam.

With their father having gone back to England to give evidence, the girls must come up with a plan of their own to get away from kidnappers Nina and Roy.

As the girls try to escape from Nina and Roy, their father refuses to make a statement to the police until he knows his daughters are safe.