Tony has settled into his new school, but things never stay the same for long - Tony's mum announces that he is going to have a new little brother or sister.
When things get too much, Tony likes to press the red button in the kitchen cupboard, and climb aboard The Invincible spaceship to chill amongst intergalactic life. This time, Tony notices a lonely looking blob hanging around space. Against the computer's warnings, Tony takes the lonely blob 'Dot' back to planet Earth so they can keep each other company.
It's fun playing space games with Dot. But, Dot is has very peculiar food habits. The school has a plumbing malfunction, does it have something to do with Dot?
Will Tony be able to come up with a plan to calm Dot down before his school presentation and the fancy dress disco? And can Dot help Tony realise how fun caring for a small creature can be?