Children's drama series. Kathy introduces Bryn and Ducket to 'Extra Terrestrial Hunt', an online programme actively looking for life beyond our planet. Suspicious goings on in Alex's garden lead Bryn to go into full conspiracy mode, and when Ducket and Lucy seemingly go missing Rachel's on board too. The mysterious goings on leave them convinced Grange Hill's been invaded by aliens, and events lead to national coverage from the press! Chloe and Andrea get comeuppance for their misdemeanours.