Samson Griffin was a human librarian. He worked in the town of Folkestone. He was the son of Harriet Griffin. He and his sister Gemma met the Eighth Doctor in the library and the three of them had numerous adventures together. Samson always called the Doctor "skipper."
Life before the Doctor
Travels with the Doctor
After meeting the Eighth Doctor in the Folkestone Library, Samson and Gemma followed him into his TARDIS. The Doctor and the two siblings travelled to several planets, including Valuensis, Porteus and Murgatroyd. They visited the Ice Caves of Shabadabadon, the court of Queen Elizabeth I, prehistoric Earth and Studio 54. (AUDIO: Terror Firma)
Encounter with Davros
After a trip to Valuensis, the trio came across a Nekkistani time cruiser. Samson and Gemma went on board to explore. They encountered Davros. He took control of their minds and made Samson knock out the Doctor. Davros used Samson to control the TARDIS, piloting it back to Earth. Davros altered the Doctor's memory so he forgot all about the siblings.
The Doctor went on his way, and met Charley Pollard and C'rizz. Samson remained subconsciously aware of the Doctor's travels, and Davros used this to monitor the Doctor. Davros had infected Gemma with a disease which mutated humans into Daleks. He used this to pave the way for the Dalek invasion of Earth.
The Doctor, Charley and C'rizz arrived on Earth and Davros sprang his trap. C'rizz joined a resistance to Daleks led by Gemma, and they attempted to make him the new Dalek emperor. This failed. In the end, the Doctor blackmailed the Daleks into leaving Earth, taking Davros with them and releasing Samson from their control. (AUDIO: Terror Firma)
Behind the scenes
While Terror Firma does not offer a date for its events, Gemma notes the novelty of "the twentieth century" and claims that everyone alive in 1958 "would be long dead before she was even born". (PROSE: Dear John)