The small town of Hamlein is peaceful and... well, pretty boring. Nothing exciting ever happens. That is, until the day an alien spaceship lands in the town square! But the critters on board are more adorable than evil, and everyone in the town is instantly enamoured by them. Only Dr Polly Piper and 12-year-old twins Tommy and Gerta Friedrichs think there's more to the alien visitors than meets the eye. Will the twins, Dr Piper and her pet pig Hamish be able to prove that the cute creatures are actually bent on taking over the town? Or will the aliens overtake the quiet town of Hamlein in their quest for world domination?