When Dani decides to get fit, she recruits the help of Ruby, an enthusiastic personal trainer, but Ruby enters Dani into a female wrestling competition. Meanwhile, Jack vows to eat more healthily, and Max competes with Ruby's little sister Maisy to make Jack crack and eat something unhealthy.

Sam is visited by a mystery astronaut sent by Nasa, who puts her through various tests as part of her application to become an astronaut. When Jack announces he is leaving on a world-sailing trip, Dani and Ruby organise a nautical-themed goodbye party.

When Sam has cold feet about leaving her friends to join the NASA training programme, Dani and Jack must show her that she would be crazy not to follow her dream. Besides, however far away Sam is, they will always be her mates.