In this completely TARDIS-based story, the crew find themselves and their ship acting very strangely indeed. Blame runs high for the Ship's unusual behavior, until the Doctor realizes the TARDIS itself may be trying to warn them...
| Actor | Role |
|---|---|
 William HartnellThe Doctor | The Doctor |
 William RussellIan Chesterton | Ian Chesterton |
 Jacqueline HillBarbara Wright | Barbara Wright |
 Carole Ann FordSusan Foreman | Susan Foreman |