H is for... Harris, Frank & Maggie

Frank Harris was a senior technician with ESGO, a company which processed natural gas from beneath the sea off the coast of England, pumping it to homes and businesses across much of the country. He and his wife Maggie lived within the grounds of the company's high security compound. Frank's boss was the bullish Robson, who demanded hard work from his staff. When Frank became concerned about unexplained pressure drops and strange sounds emanating from the pipelines, Robson refused to heed his warnings. He found an ally in the Doctor, however, when he and companions Jamie and Victoria inadvertently trespassed onto ESGO land. A pair of maintenance men - Oak and Quill - who had first been sent to investigate the strange phenomena had become mentally enslaved by a sentient seaweed creature which the gas drilling had disturbed. They were dispatched to stop Frank from investigating further, and attacked Maggie in her home. After being overpowered by a toxic gas they emitted, she was compelled to walk out into the sea - another mental slave of the weed creature. Frank took charge after Robson suffered a mental breakdown and was then taken over by the weed, and he helped the Doctor defeat it - forcing it back into the depths of the sea thanks to Victoria's amplified screaming. The weed released its slaves once it had retreated, and Maggie was returned unharmed. Victoria decided she no longer wanted to continue travelling in the TARDIS due to the terrors she had been forced to face, and Frank and Maggie agreed to let her stay with them.

Played by: Roy Spencer (Frank) and June Murphy (Maggie). Appearances: Fury From The Deep (1968).

• Both actors appeared in one other role apiece in Doctor Who. Spencer had been Manyak, who defended the First Doctor and his companions when put on trial in the first half of The Ark. Murphy's other role also had a nautical flavour, as she was 3rd Officer Jane Blythe in The Sea Devils. Its director, Michael E Briant, had been the Production Assistant on Fury From The Deep.