Purporting to be an investigation into the UK's contemporary "brain drain", Alternative 3 uncovered a plan to make the Moon and Mars habitable in the event of climate change and a terminal environmental catastrophe on Earth.
| Actor | Role |
|---|---|
| TTim BrintonHimself | Himself |
| GGregory MunroeColin Benson | Colin Benson |
| CCarol HazellKatherine White | Katherine White |
 Shane RimmerBob Grodin | Bob Grodin |
 Richard MarnerDr. Carl Gerstein | Dr. Carl Gerstein |
| AAlec LinsteadProfessor Broadbent | Professor Broadbent |
 David BaxtNot listed | Not listed |
 Norman ChancerNot listed | Not listed |
| AAnthony RoyeNot listed | Not listed |
| PPatsy TrenchNot listed | Not listed |
 Phoebe NichollsNot listed | Not listed |
 Ivor RobertsNot listed | Not listed |
| LLinda CunninghamNot listed | Not listed |
| NNancy AdamsNot listed | Not listed |
| JJonathan Hieatt-SmithNot listed | Not listed |
| AAlice WadeNot listed | Not listed |