Ryzt

Lord Ryzt led an attempted invasion of Earth in 1912. His force took over the household of Lord Cranarch just before the Doctor was due to arrive for dinner. They used their ‘dullifiers’ to hypnotise and drain the memories of their hosts. Lord Cranarch had once held a position high in British intelligence and so would have given away secrets of the defence of the country. The Doctor intervened and turned the alien technology against the them, persuading them that Earth wasn’t worth bothering about and they should return home. (DWA: The Demons of Repton Abbey)