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...