Arabella Twigg is an ordinary girl. Her father invents things that don’t work. Her mother cooks food no one can eat and her horrid brother, Tom, likes to get her into trouble. Her Gran is crazy but loves Arabella very much.

Arabella’s life was boring until strange things began to happen to her. One day, she is out eating pizza and then suddenly she finds herself with her brother, Tom, in the middle of the Great Siege of Malta in 1565 when the Knights of St. John showed great courage and fortitude in fighting off an invasion from the Turkish Empire.

Will they join Grandmaster Valette in battle?