Alien Grimstink has travelled ninety thousand light years to annihilate all life on Earth. 13-year-old Layla Tenby has travelled half a mile to deliver leaflets for affordable fence panels. But, when they swap places, Grimstink finds himself battling traffic wardens and the Subway sandwich ordering system, while Layla is zapped to a strange planet and left fighting for the future of the galaxy whether she wants to or not (spoiler: she does not want to). Is Reece, Layla's annoying younger brother, key to the galaxy's survival, or will his friendship with new bestie Grimstink lead them all to impending doom? From black holes to shopping precincts; from mining satellites to old people's homes; from quantum spaceships to the middle aisle of Aldi. Is this the end of all life on Planet Earth... ... or the beginning of a beautiful friendship?