The Primary and Secondary Phases were aired , in a slightly edited version , in the United States on NPR Playhouse .
This episode was released as part of the second radio series and , later , The Secondary Phase on cassettes and CDs .
The The Secondary Phase       were aired , in a slightly edited version , in the United States on NPR Playhouse .
This episode was released as part of the second radio series and , later , The Secondary Phase on cassettes and CDs .