The Doctor and Peri visit the planet Targos Delta to check in on old friend Professor Albrecht Thompson, only to discover that he has vanished. The Doctor's curiosity is piqued. They must investigate, but they must do so stealthily...
- ISBN10 1844354482
- ISBN13 9781844354481
- Publish Date 31 March 2010
- Publish Status Out of Print
- Out of Print 12 November 2021
- Publish Country GB
- Imprint Big Finish Productions Ltd
- Format Audiobook
- Duration 1 hours and 40 minutes
- Language English