The TARDIS lands in London where the Doctor, Jamie and Zoe agree to help find Isobel Watkins' missing uncle. Searching for Professor Watkins at his last place of work, a multinational electronics supplier, he meets the company's managing director. He's not what he seems - and possesses alien technology in his office.
| Name | Type | Role | |
|---|---|---|---|
| Derrick Sherwin | Writer | ||
| Geoffrey Cheshire | Guest Star | ||
| Murray Evans | Guest Star | ||
| Douglas Camfield | Director |