Agatha Christie’s characters were electrocuted, shot, stabbed, and occasionally shoved off cliffs. But more often than not, says chemist-turned-author Kathryn Harkup, they were poisoned. Over 83 detective books, Christie killed hundreds of characters using poisons as diverse as digitalis (foxglove), strychnine, and thallium, and she won praise from chemists for her scientific accuracy. Harkups talks with Ira about the many poisons Dame Agatha employed, and explains how the “Queen of Crime” grew to know so much about chemistry’s dark side.

Read an excerpt from Kathryn Harkup’s book, A is for Arsenic: The Poisons of Agatha Christie. For more fact cards, like the one below, about the poisons Agatha Christie used, click here.