How do we smell? When Jack's new invisible probe goes out of control, his pals must find it before the alien device causes unseen mayhem around the city.

Jack is a small alien who finds everything on Earth fascinating. Spurred on by his insatiable need to learn about creatures and phenomena from Earth and outer space, Jack boldly yet recklessly guides his alien friends through some tricky adventures. Developed for children from six to nine years old, Jack mixes humour, adventure, and science. The series helps children discover amazing new facts about the world and space around them.