The TARDIS arrives on Earth in a new ice age. The travellers make their way into a base where scientists, commanded by Leader Clent, are using an ioniser device to combat the advance of a glacier.
| Directing | Derek Martinus | Director |
| Writing | Brian Hayles | Writer |
| Production | Innes Lloyd | Producer |
| Writing | Peter Bryant | Script Editor |
| Sound | Dudley Simpson | Music |
