We spend most of the hour with Simon Parkin, author of "The Forbidden Garden: The Botanists of Besieged Leningrad and their Impossible Choice." The book tells the extraordinary and true story of the Plant Institute, the world's first significant seed depository, located in Leningrad- and the courageous efforts of its staff members to safeguard the depository during the horrific months when the city was under siege from Nazi Germany. We'll do a follow-up interview with Curzio Caravati, who is a participant in a similar sort of archive .... one devoted to preserving many varieties of potatoes.