In this episode, Michigan State University historian of science Kristie Macrakis discusses the use of radioactive isotopes in the cloak and dagger world of cold war espionage, and what it tells us about the polonium poisoning of Alexander Litvinenko. We'll also hear a Christmas poem dedicated to the graduate students and postdocs who burn the midnight oil even on Christmas Eve. Plus we'll test your knowledge about some recent science in the news. Websites mentioned on this episode include blog.sciam.com; www.sciam.com/podcast; www.sciam.com/news