Roy sees a strange blue light in the garden and convinces Tristan it's aliens! Despite reassurance from Maura, Roy's imagination goes into overdrive as Tristan and he gather together an alien detective kit and search for clues of extraterrestrial activity. They discover a slime trail in the garden, strange footprints in the soil, and what appears to be a UFO landing pad in the grass! The clues are mounting up and things go galactic when Roy is convinced he's been zapped by aliens. What exactly is in Mr Barker's shed?