The TARDIS is drawn by a mysterious force and lands on the alien planet Vortis. There the Doctor, Ian, Barbara and Vicki find themselves caught up in a war between an evil force known as "The Animus", its ant-like Zarbi allies, and the butterfly-like Menoptra race and their allies the subterranean Optera.
| Creator | C. E. Webber |
|---|---|
| Actor | Sylvester McCoy, Sophie Aldred |
| Country | United Kingdom |
| Production | BBC |