Case of the Missing Kanushu/Devolution City

An ancient witch doctor uses her powers to devolve a advanced alien civilization into cave people, and plots to turn an entire planet into a black hole. Meanwhile, on Earth, Noah tries to prove that nearby crop circles show signs of aliens. Case of the Missing Kanushu: Betty is called to Spindley Tam's fortress to investigate his mysterious disappearance whilst, on Earth, Noah presents a rare coin for show-and-tell.