Mashka is unaware of the dangers. Tail wagging, ears flopping, she bounds down dirt paths, through tall grass, past rubble to cooling tower number five. An unofficial tour guide, the stray dog leads artist Julia Oldham into the enormous structure. Then Mashka, glossy black and spry, lies down on the moss-covered concrete floor of the soaring cylindrical tower and happily chews on some elk bones, blissfully oblivious to the radioactive isotopic dust that blankets her world.