The future. The TAU-mode shuttle carries passengers to Australia through the earth's crust. When a routine TAU-shuttle becomes entombed in solid rock miles under the earth, the only means of rescue is the experimental LAMBDA-mode shuttle; which its creator is unsure about.
| Directing | George Spenton-Foster | Director |
| Writing | Colin Kapp | Story |
| Writing | Bruce Stewart | Adaptation |
| Production | Irene Shubik | Producer |