<p>Philippe travels to Albuquerque to meet Tom Lucid Jnr, the son of the CIA agent who recruited Karl Hass, chief source on Project Los Angeles and the man Otto had lunch with on Lake Albano. How much does he know about his father's role in recruiting Nazis and a close relative in Geneva?
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</p>

The Ratline: 10. Persilschein

Twenty-five years on from the deadliest terror attack in history, BBC investigative journalist Jane McMullen asks why thousands of grieving families are still fighting for answers.  
 
In early 2000, two young Saudis arrived in San Diego. They had never been to America, spoke almost no English, and had no idea how to open a bank account or rent a flat. Within weeks they had done all of it. Twenty months later they hijacked a plane and crashed it into the Pentagon. 
 
McMullen investigates the hidden story of a man who helped two of the hijackers - and reveals a story that the US and Saudi governments have fought to keep secret.