Philippe Sands accesses the Vatican archives to find out about Otto's protector in Rome, the man who was by his side as he lay dying, Alois Hudal. Hudal's archivist reveals to the team something extraordinary.
Producer: Gemma Newby
Sound design: Neil Churchill
Research: James Everest and Lea Main-Klingst
Original music by Catrin Finch and Sekou Keita
Otto Wachter: Stephen Fry
Charlotte Wachter: Laura Linney
Other parts by members of the BBC Radio Drama Company